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same excitation and emission peaks

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Charu Tanwar

same excitation and emission peaks

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Dear List

Not a direct confocal related query.
Anyone please let me know whether any metallic nanoparticle with a definite size
can have the same emission peak as its excitation peak???

Thanks in advance

Charu Tanwar
Imaging Specialist
Advanced Instrumentation Research Facility
Jawaharlal Nehru University
New Delhi
India.

mcammer

Re: same excitation and emission peaks

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Are you seeing reflectance? We used to use the confocal in reflectance mode to look at lead ATPase reaction product in liver and nickle enhanced gold immuno.

_________________________________________
Michael Cammer, Assistant Research Scientist
Skirball Institute of Biomolecular Medicine
Lab: (212) 263-3208 Cell: (914) 309-3270

________________________________________
From: Confocal Microscopy List [[hidden email]] On Behalf Of Charu Tanwar [[hidden email]]
Sent: Wednesday, April 27, 2011 9:59 AM
To: [hidden email]
Subject: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear List

Not a direct confocal related query.
Anyone please let me know whether any metallic nanoparticle with a definite size
can have the same emission peak as its excitation peak???

Thanks in advance

Charu Tanwar
Imaging Specialist
Advanced Instrumentation Research Facility
Jawaharlal Nehru University
New Delhi
India.

------------------------------------------------------------
This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
=================================

Jeffrey L. Travis

Re: same excitation and emission peaks

In reply to this post by Charu Tanwar

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Wouldn't that violate the Second Law?

On 4/27/2011 9:59 AM, Charu Tanwar wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear List
>
> Not a direct confocal related query.
> Anyone please let me know whether any metallic nanoparticle with a definite size
> can have the same emission peak as its excitation peak???
>
> Thanks in advance
>
> Charu Tanwar
> Imaging Specialist
> Advanced Instrumentation Research Facility
> Jawaharlal Nehru University
> New Delhi
> India.
>
>

Mark Cannell

Re: same excitation and emission peaks

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No, because the decay modes of the phonon is probabilistic.

Cheers

On 28/04/2011, at 2:03 AM, Jeffrey L. Travis wrote:

>
>
> Wouldn't that violate the Second Law?
>
>
> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
>>
>>
>> Dear List
>>
>> Not a direct confocal related query.
>> Anyone please let me know whether any metallic nanoparticle with a
>> definite size
>> can have the same emission peak as its excitation peak???
>>
>> Thanks in advance
>>
>> Charu Tanwar
>> Imaging Specialist
>> Advanced Instrumentation Research Facility
>> Jawaharlal Nehru University
>> New Delhi
>> India.
>>
>>

Charu Tanwar

Re: same excitation and emission peaks

In reply to this post by mcammer

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Dear Michael

We got the excitation peak and emission peak data for these nanoparticles from flourimeter (we scanned the particles in the range 200nm - 700nm and we got one excitation peak at 350nm. Subsequently we got 2 emission peaks at 350nm and 700nm). After confirming the excitation and emission spectra we need to study theses particles insde cellualr system through confocal microscopy.

CHARU TANWAR
Imaging Specialist
Advanced Instrumentation Research Facility
Jawaharlal Nehru University
New Delhi 110067
India.

--- On Wed, 27/4/11, Cammer, Michael <[hidden email]> wrote:

From: Cammer, Michael <[hidden email]>
Subject: Re: same excitation and emission peaks
To: [hidden email]
Date: Wednesday, 27 April, 2011, 7:31 PM

*****
To join, leave or search the confocal microscopy listserv, go to:
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*****

Are you seeing reflectance? We used to use the confocal in reflectance mode to look at lead ATPase reaction product in liver and nickle enhanced gold immuno.

_________________________________________
Michael Cammer, Assistant Research Scientist
Skirball Institute of Biomolecular Medicine
Lab: (212) 263-3208 Cell: (914) 309-3270

________________________________________
From: Confocal Microscopy List [[hidden email]] On Behalf Of Charu Tanwar [[hidden email]]
Sent: Wednesday, April 27, 2011 9:59 AM
To: [hidden email]
Subject: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear List

Not a direct confocal related query.
Anyone please let me know whether any metallic nanoparticle with a definite size
can have the same emission peak as its excitation peak???

Thanks in advance

Charu Tanwar
Imaging Specialist
Advanced Instrumentation Research Facility
Jawaharlal Nehru University
New Delhi
India.

------------------------------------------------------------
This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
=================================

Charu Tanwar

Re: same excitation and emission peaks

In reply to this post by Jeffrey L. Travis

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yes...that is what i also thought of. But this is the data we are getting after repeatedly doing the experiment.
Thanks

CHARU TANWAR
Imaging Specialist
Advanced Instrumentation Research Facility
Jawaharlal Nehru University
New Delhi 110067
India.

--- On Wed, 27/4/11, Jeffrey L. Travis <[hidden email]> wrote:

From: Jeffrey L. Travis <[hidden email]>
Subject: Re: same excitation and emission peaks
To: [hidden email]
Date: Wednesday, 27 April, 2011, 7:33 PM

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*****

Wouldn't that violate the Second Law?

On 4/27/2011 9:59 AM, Charu Tanwar wrote:

Sudipta Maiti

Re: same excitation and emission peaks

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are you not just looking at Rayleigh scattering?
Sudipta
On Thu, 28 Apr 2011 12:24:29 +0530, charu tanwar wrote

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> yes...that is what i also thought of. But this is the data we are
> getting after repeatedly doing the experiment. Thanks
>
> CHARU TANWAR
> Imaging Specialist
> Advanced Instrumentation Research Facility
> Jawaharlal Nehru University
> New Delhi 110067
> India.
>
> --- On Wed, 27/4/11, Jeffrey L. Travis <[hidden email]> wrote:
>
> From: Jeffrey L. Travis <[hidden email]>
> Subject: Re: same excitation and emission peaks
> To: [hidden email]
> Date: Wednesday, 27 April, 2011, 7:33 PM
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Wouldn't that violate the Second Law?
>
> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
> > *****
> > To join, leave or search the confocal microscopy listserv, go to:
> > http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> > *****
> >
> > Dear List
> >
> > Not a direct confocal related query.
> > Anyone please let me know whether any metallic nanoparticle with a

definite size

> > can have the same emission peak as its excitation peak???
> >
> > Thanks in advance
> >
> > Charu Tanwar
> > Imaging Specialist
> > Advanced Instrumentation Research Facility
> > Jawaharlal Nehru University
> > New Delhi
> > India.
> >
> >

Dr. Sudipta Maiti
Associate Professor
Dept. of Chemical Sciences
Tata Institute of Fundamental Research
Homi Bhabha Raod, Colaba, Mumbai 400005
Ph. 91-22-2278-2716 / 2539
Fax: 91-22-2280-4610
alternate e-mail: [hidden email]
url: biophotonics.wetpaint.com

Johannes-P. Koch

Re: same excitation and emission peaks

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*****

Think so too; if you measure something in a fluorimeter, you always get
a scattering "line" or peak (if looking at your spectra in 2D)!

Mark, could you comment on your phonon stuff?

To my knowledge, phonons as such do not fluoresce; they do interact with
photons, i.e. you can generate a fluorescing photon by annihilating a
phonon or vice versa; still wherever you go, their is some loss of
energy, meaning that you cannot have exactly the same peaks. -
probabilistic or not!

Johannes

Am 28.04.2011 08:57, schrieb Sudipta Maiti:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> are you not just looking at Rayleigh scattering?
> Sudipta
> On Thu, 28 Apr 2011 12:24:29 +0530, charu tanwar wrote
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> yes...that is what i also thought of. But this is the data we are
>> getting after repeatedly doing the experiment. Thanks
>>
>> CHARU TANWAR
>> Imaging Specialist
>> Advanced Instrumentation Research Facility
>> Jawaharlal Nehru University
>> New Delhi 110067
>> India.
>>
>> --- On Wed, 27/4/11, Jeffrey L. Travis<[hidden email]> wrote:
>>
>> From: Jeffrey L. Travis<[hidden email]>
>> Subject: Re: same excitation and emission peaks
>> To: [hidden email]
>> Date: Wednesday, 27 April, 2011, 7:33 PM
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Wouldn't that violate the Second Law?
>>
>> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Dear List
>>>
>>> Not a direct confocal related query.
>>> Anyone please let me know whether any metallic nanoparticle with a
> definite size
>>> can have the same emission peak as its excitation peak???
>>>
>>> Thanks in advance
>>>
>>> Charu Tanwar
>>> Imaging Specialist
>>> Advanced Instrumentation Research Facility
>>> Jawaharlal Nehru University
>>> New Delhi
>>> India.
>>>
>>>
>
>
> Dr. Sudipta Maiti
> Associate Professor
> Dept. of Chemical Sciences
> Tata Institute of Fundamental Research
> Homi Bhabha Raod, Colaba, Mumbai 400005
> Ph. 91-22-2278-2716 / 2539
> Fax: 91-22-2280-4610
> alternate e-mail: [hidden email]
> url: biophotonics.wetpaint.com
>

--
Mag. Johannes-P. KOCH
Department of Biochemistry and Cell Biology
MFPL, University of Vienna
Dr. Bohrgasse 9/5
A-1030 Vienna
Austria

phone: 0043 1 4277 52809
fax: 0043 1 4277 9528

mail to: [hidden email]

Charu Tanwar

Re: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Yes that might be the case.
it may be just the scattering peak, but i wonder it is so sharp and well defined curve as we get in a spectra.
Thanks for valuable advices.

CHARU TANWAR
Imaging Specialist
Advanced Instrumentation Research Facility
Jawaharlal Nehru University
New Delhi 110067
India.

--- On Thu, 28/4/11, Johannes-P. Koch <[hidden email]> wrote:

From: Johannes-P. Koch <[hidden email]>
Subject: Re: same excitation and emission peaks
To: [hidden email]
Date: Thursday, 28 April, 2011, 12:57 PM

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Think so too; if you measure something in a fluorimeter, you always get
a scattering "line" or peak (if looking at your spectra in 2D)!

Mark, could you comment on your phonon stuff?

To my knowledge, phonons as such do not fluoresce; they do interact with
photons, i.e. you can generate a fluorescing photon by annihilating a
phonon or vice versa; still wherever you go, their is some loss of
energy, meaning that you cannot have exactly the same peaks. -
probabilistic or not!

Johannes

Am 28.04.2011 08:57, schrieb Sudipta Maiti:

Andreas Bruckbauer

Re: same excitation and emission peaks

In reply to this post by Johannes-P. Koch

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

To distinguish between Rayleigh or Mie scattering ('reflection') and photoluminescence you would need to measure time resolved, see e.g. G. Plesson et al. PHYSICAL REVIEW B 70, 205424 (2004). What you measure is most likely the excitation light, but you could try to vary the with of the excitation line if this is possible in your instrument and see if the peak varies accordingly.

I think what Mark meant was the interaction of the excited electron with phonons, usually the energy is dissipated as phonons but you could also have phonons transferring energy to the electron in which case it would gain energy from the phonon. If it does not relax further and goes back into the ground state by emitting a photon, you will get anti stokes fluorescence. At room temperature the energy of a single phonon would be around kT (25 meV compared to 3 eV for a blue photon), so you need a lot of electron-phonon interaction to make a noticable shift.

In case of the metal particle you will also have plasmon excitation.

best wishes

Andreas

-----Original Message-----
From: Johannes-P. Koch <[hidden email]>
To: [hidden email]
Sent: Thu, 28 Apr 2011 8:27
Subject: Re: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Think so too; if you measure something in a fluorimeter, you always get a scattering "line" or peak (if looking at your spectra in 2D)!

Mark, could you comment on your phonon stuff?

To my knowledge, phonons as such do not fluoresce; they do interact with photons, i.e. you can generate a fluorescing photon by annihilating a phonon or vice versa; still wherever you go, their is some loss of energy, meaning that you cannot have exactly the same peaks. - probabilistic or not!

Johannes

Am 28.04.2011 08:57, schrieb Sudipta Maiti:

-- Mag. Johannes-P. KOCH
Department of Biochemistry and Cell Biology
MFPL, University of Vienna
Dr. Bohrgasse 9/5
A-1030 Vienna
Austria

phone: 0043 1 4277 52809
fax: 0043 1 4277 9528

mail to: [hidden email]

Mark Cannell

Re: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Quite so. But in this case he's not looking for an antistokes shift
just re-emission of the same apparent energy. It's the lower
probability of re-emission at this wavelength that prevents violation
of the second law.

Cheers

On 28/04/2011, at 10:30 PM, Andreas Bruckbauer wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
>
>
> To distinguish between Rayleigh or Mie scattering ('reflection') and
> photoluminescence you would need to measure time resolved, see e.g.
> G. Plesson et al. PHYSICAL REVIEW B 70, 205424 (2004). What you
> measure is most likely the excitation light, but you could try to
> vary the with of the excitation line if this is possible in your
> instrument and see if the peak varies accordingly.
>
> I think what Mark meant was the interaction of the excited electron
> with phonons, usually the energy is dissipated as phonons but you
> could also have phonons transferring energy to the electron in which
> case it would gain energy from the phonon. If it does not relax
> further and goes back into the ground state by emitting a photon,
> you will get anti stokes fluorescence. At room temperature the
> energy of a single phonon would be around kT (25 meV compared to 3
> eV for a blue photon), so you need a lot of electron-phonon
> interaction to make a noticable shift.
>
> In case of the metal particle you will also have plasmon excitation.
>
> best wishes
>
> Andreas
>
>
>
>
>
>
> -----Original Message-----
> From: Johannes-P. Koch <[hidden email]>
> To: [hidden email]
> Sent: Thu, 28 Apr 2011 8:27
> Subject: Re: same excitation and emission peaks
>
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Think so too; if you measure something in a fluorimeter, you always
> get a scattering "line" or peak (if looking at your spectra in 2D)!
>
>
> Mark, could you comment on your phonon stuff?
>
> To my knowledge, phonons as such do not fluoresce; they do interact
> with photons, i.e. you can generate a fluorescing photon by
> annihilating a phonon or vice versa; still wherever you go, their is
> some loss of energy, meaning that you cannot have exactly the same
> peaks. - probabilistic or not!
>
> Johannes
>
> Am 28.04.2011 08:57, schrieb Sudipta Maiti:
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> are you not just looking at Rayleigh scattering?
>> Sudipta
>> On Thu, 28 Apr 2011 12:24:29 +0530, charu tanwar wrote
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> yes...that is what i also thought of. But this is the data we are
>>> getting after repeatedly doing the experiment. Thanks
>>>
>>> CHARU TANWAR
>>> Imaging Specialist
>>> Advanced Instrumentation Research Facility
>>> Jawaharlal Nehru University
>>> New Delhi 110067
>>> India.
>>>
>>> --- On Wed, 27/4/11, Jeffrey L. Travis<[hidden email]> wrote:
>>>
>>> From: Jeffrey L. Travis<[hidden email]>
>>> Subject: Re: same excitation and emission peaks
>>> To: [hidden email]
>>> Date: Wednesday, 27 April, 2011, 7:33 PM
>>>
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Wouldn't that violate the Second Law?
>>>
>>> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> Dear List
>>>>
>>>> Not a direct confocal related query.
>>>> Anyone please let me know whether any metallic nanoparticle with a
>> definite size
>>>> can have the same emission peak as its excitation peak???
>>>>
>>>> Thanks in advance
>>>>
>>>> Charu Tanwar
>>>> Imaging Specialist
>>>> Advanced Instrumentation Research Facility
>>>> Jawaharlal Nehru University
>>>> New Delhi
>>>> India.
>>>>
>>>>
>>
>>
>> Dr. Sudipta Maiti
>> Associate Professor
>> Dept. of Chemical Sciences
>> Tata Institute of Fundamental Research
>> Homi Bhabha Raod, Colaba, Mumbai 400005
>> Ph. 91-22-2278-2716 / 2539
>> Fax: 91-22-2280-4610
>> alternate e-mail: [hidden email]
>> url: biophotonics.wetpaint.com
>>
>
> -- Mag. Johannes-P. KOCH
> Department of Biochemistry and Cell Biology
> MFPL, University of Vienna
> Dr. Bohrgasse 9/5
> A-1030 Vienna
> Austria
>
> phone: 0043 1 4277 52809
> fax: 0043 1 4277 9528
>
> mail to: [hidden email]
>
>
>

Coutu, Cathy

Re: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Sorry, but I'm not familiar with an "antistokes shift". Would that be an emission with a shorter wavelength than the excitation???

Cathy

Cathy Coutu, M. Sc.
Technician / Technicienne
Genomics, Bioinformatics, and other Bioinformation / Génomique, Bioinformatique et Bioinformation
Agriculture and Agri-Food Canada/Agriculture et Agroalimentaire Canada
107 Science place / 107 Place Science
Saskatoon, Saskatchewan / Saskatoon (Saskatchewan)
S7N 0X2
[hidden email]
Telephone/Téléphone: 306-956-2801
Facsimile/Télécopieur: 306-956-7247
Teletypewriter | Téléimprimeur 613-773-2600
Government of Canada | Gouvernement du Canada

-----Original Message-----
From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Mark Cannell
Sent: April-28-11 4:43 AM
To: [hidden email]
Subject: Re: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Quite so. But in this case he's not looking for an antistokes shift
just re-emission of the same apparent energy. It's the lower
probability of re-emission at this wavelength that prevents violation
of the second law.

Cheers

On 28/04/2011, at 10:30 PM, Andreas Bruckbauer wrote:

Johannes-P. Koch

Re: same excitation and emission peaks

In reply to this post by Andreas Bruckbauer

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I think a very easy way to determine this is to measure the fluorscence
not only at a single excitation wavelength but over a whole spectrum
(e.g.350-700nm). Then by looking at your spectra (x =excitation,
y=emission, z= Intensity), you should see a continuous peak (diagonal)
that crosses your spectrum at a 45° angle (i.e. emission=excitation).
That is your scattering. Other peaks at higher emission wavelengths
usually represent fluorescence!

Usually, fluorimeters are build with a 90° geometry to avoid the
detector measuring excitation light directly. However, some light is
scattered and that is what you see.

Johannes

PS: Thanks for the clarification concerning the phonons.

Am 28.04.2011 12:30, schrieb Andreas Bruckbauer:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
>
>
> To distinguish between Rayleigh or Mie scattering ('reflection') and photoluminescence you would need to measure time resolved, see e.g. G. Plesson et al. PHYSICAL REVIEW B 70, 205424 (2004). What you measure is most likely the excitation light, but you could try to vary the with of the excitation line if this is possible in your instrument and see if the peak varies accordingly.
>
> I think what Mark meant was the interaction of the excited electron with phonons, usually the energy is dissipated as phonons but you could also have phonons transferring energy to the electron in which case it would gain energy from the phonon. If it does not relax further and goes back into the ground state by emitting a photon, you will get anti stokes fluorescence. At room temperature the energy of a single phonon would be around kT (25 meV compared to 3 eV for a blue photon), so you need a lot of electron-phonon interaction to make a noticable shift.
>
> In case of the metal particle you will also have plasmon excitation.
>
> best wishes
>
> Andreas
>
>
>
>
>
>
> -----Original Message-----
> From: Johannes-P. Koch<[hidden email]>
> To: [hidden email]
> Sent: Thu, 28 Apr 2011 8:27
> Subject: Re: same excitation and emission peaks
>
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Think so too; if you measure something in a fluorimeter, you always get a scattering "line" or peak (if looking at your spectra in 2D)!
>
>
> Mark, could you comment on your phonon stuff?
>
> To my knowledge, phonons as such do not fluoresce; they do interact with photons, i.e. you can generate a fluorescing photon by annihilating a phonon or vice versa; still wherever you go, their is some loss of energy, meaning that you cannot have exactly the same peaks. - probabilistic or not!
>
> Johannes
>
> Am 28.04.2011 08:57, schrieb Sudipta Maiti:
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> are you not just looking at Rayleigh scattering?
>> Sudipta
>> On Thu, 28 Apr 2011 12:24:29 +0530, charu tanwar wrote
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> yes...that is what i also thought of. But this is the data we are
>>> getting after repeatedly doing the experiment. Thanks
>>>
>>> CHARU TANWAR
>>> Imaging Specialist
>>> Advanced Instrumentation Research Facility
>>> Jawaharlal Nehru University
>>> New Delhi 110067
>>> India.
>>>
>>> --- On Wed, 27/4/11, Jeffrey L. Travis<[hidden email]> wrote:
>>>
>>> From: Jeffrey L. Travis<[hidden email]>
>>> Subject: Re: same excitation and emission peaks
>>> To: [hidden email]
>>> Date: Wednesday, 27 April, 2011, 7:33 PM
>>>
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Wouldn't that violate the Second Law?
>>>
>>> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> Dear List
>>>>
>>>> Not a direct confocal related query.
>>>> Anyone please let me know whether any metallic nanoparticle with a
>> definite size
>>>> can have the same emission peak as its excitation peak???
>>>>
>>>> Thanks in advance
>>>>
>>>> Charu Tanwar
>>>> Imaging Specialist
>>>> Advanced Instrumentation Research Facility
>>>> Jawaharlal Nehru University
>>>> New Delhi
>>>> India.
>>>>
>>>>
>>
>>
>> Dr. Sudipta Maiti
>> Associate Professor
>> Dept. of Chemical Sciences
>> Tata Institute of Fundamental Research
>> Homi Bhabha Raod, Colaba, Mumbai 400005
>> Ph. 91-22-2278-2716 / 2539
>> Fax: 91-22-2280-4610
>> alternate e-mail: [hidden email]
>> url: biophotonics.wetpaint.com
>>
>
> -- Mag. Johannes-P. KOCH
> Department of Biochemistry and Cell Biology
> MFPL, University of Vienna
> Dr. Bohrgasse 9/5
> A-1030 Vienna
> Austria
>
> phone: 0043 1 4277 52809
> fax: 0043 1 4277 9528
>
> mail to: [hidden email]
>
>
>
>

S. Brunet

Re: same excitation and emission peaks

In reply to this post by Charu Tanwar

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Hi,
Is your emission peak at 700nm from excitation at 350nm?
If so, did you verify that it is not due to 2nd order diffraction of 350nm from
the emission monochromator?
Bye,
Sophie
____________________________________________________
Sophie M. K. Brunet, Ph. D.
Research Officer
Optical Spectroscopy, Laser Systems and Applications
[hidden email]
306-966-1719 (office) 306-966-1702 (fax)
____________________________________________________
Saskatchewan Structural Sciences Centre
University of Saskatchewan
Thorvaldson Bldg.
110 Science Place
Saskatoon, Sk S7N 5C9
____________________________________________________

Quoting charu tanwar <[hidden email]>:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear Michael
>
> We got the excitation peak and emission peak data for these nanoparticles
> from flourimeter (we scanned the particles in the range 200nm - 700nm and we
> got one excitation peak at 350nm. Subsequently we got 2 emission peaks at
> 350nm and 700nm). After confirming the excitation and emission spectra we
> need to study theses particles insde cellualr system through confocal
> microscopy.
>
> CHARU TANWAR
> Imaging Specialist
> Advanced Instrumentation Research Facility
> Jawaharlal Nehru University
> New Delhi 110067
> India.
>
> --- On Wed, 27/4/11, Cammer, Michael <[hidden email]> wrote:
>
>
> From: Cammer, Michael <[hidden email]>
> Subject: Re: same excitation and emission peaks
> To: [hidden email]
> Date: Wednesday, 27 April, 2011, 7:31 PM
>
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Are you seeing reflectance? We used to use the confocal in reflectance mode
> to look at lead ATPase reaction product in liver and nickle enhanced gold
> immuno.
>
> _________________________________________
> Michael Cammer, Assistant Research Scientist
> Skirball Institute of Biomolecular Medicine
> Lab: (212) 263-3208 Cell: (914) 309-3270
>
> ________________________________________
> From: Confocal Microscopy List [[hidden email]] On Behalf
> Of Charu Tanwar [[hidden email]]
> Sent: Wednesday, April 27, 2011 9:59 AM
> To: [hidden email]
> Subject: same excitation and emission peaks
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Dear List
>
> Not a direct confocal related query.
> Anyone please let me know whether any metallic nanoparticle with a definite
> size
> can have the same emission peak as its excitation peak???
>
> Thanks in advance
>
> Charu Tanwar
> Imaging Specialist
> Advanced Instrumentation Research Facility
> Jawaharlal Nehru University
> New Delhi
> India.
>
> ------------------------------------------------------------
> This email message, including any attachments, is for the sole use of the
> intended recipient(s) and may contain information that is proprietary,
> confidential, and exempt from disclosure under applicable law. Any
> unauthorized review, use, disclosure, or distribution is prohibited. If you
> have received this email in error please notify the sender by return email
> and delete the original message. Please note, the recipient should check this
> email and any attachments for the presence of viruses. The organization
> accepts no liability for any damage caused by any virus transmitted by this
> email.
> =================================
>

Mark Cannell

Re: same excitation and emission peaks

In reply to this post by Coutu, Cathy

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Yes:
"When a system (be it a molecule or atom) absorbs a photon, it gains
energy and enters an excited state. One way for the system to relax is
to emit a photon, thus losing its energy (another method would be the
loss of heat energy). When the emitted photon has less energy than the
absorbed photon, this energy difference is the Stokes shift. If the
emitted photon has more energy, the energy difference is called an
anti-Stokes shift;[3] this extra energy comes from dissipation of
thermal phonons in a crystal lattice, cooling the crystal in the
process. Yttrium oxysulfidedoped with gadolinium oxysulfide is a
common industrial anti-Stokes pigment, absorbing in the near-infrared
and emitting in the visible portion of the spectrum."
http://en.wikipedia.org/wiki/Stokes_shift

Hope this helps, Mark

On 29/04/2011, at 2:10 AM, Coutu, Cathy wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Sorry, but I'm not familiar with an "antistokes shift". Would that
> be an emission with a shorter wavelength than the excitation???
>
> Cathy
>
> Cathy Coutu, M. Sc.
> Technician / Technicienne
> Genomics, Bioinformatics, and other Bioinformation / Génomique,
> Bioinformatique et Bioinformation
> Agriculture and Agri-Food Canada/Agriculture et Agroalimentaire Canada
> 107 Science place / 107 Place Science
> Saskatoon, Saskatchewan / Saskatoon (Saskatchewan)
> S7N 0X2
> [hidden email]
> Telephone/Téléphone: 306-956-2801
> Facsimile/Télécopieur: 306-956-7247
> Teletypewriter | Téléimprimeur 613-773-2600
> Government of Canada | Gouvernement du Canada
>
> -----Original Message-----
> From: Confocal Microscopy List [mailto:[hidden email]
> ] On Behalf Of Mark Cannell
> Sent: April-28-11 4:43 AM
> To: [hidden email]
> Subject: Re: same excitation and emission peaks
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Quite so. But in this case he's not looking for an antistokes shift
> just re-emission of the same apparent energy. It's the lower
> probability of re-emission at this wavelength that prevents violation
> of the second law.
>
> Cheers
>
> On 28/04/2011, at 10:30 PM, Andreas Bruckbauer wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>>
>>
>> To distinguish between Rayleigh or Mie scattering ('reflection') and
>> photoluminescence you would need to measure time resolved, see e.g.
>> G. Plesson et al. PHYSICAL REVIEW B 70, 205424 (2004). What you
>> measure is most likely the excitation light, but you could try to
>> vary the with of the excitation line if this is possible in your
>> instrument and see if the peak varies accordingly.
>>
>> I think what Mark meant was the interaction of the excited electron
>> with phonons, usually the energy is dissipated as phonons but you
>> could also have phonons transferring energy to the electron in which
>> case it would gain energy from the phonon. If it does not relax
>> further and goes back into the ground state by emitting a photon,
>> you will get anti stokes fluorescence. At room temperature the
>> energy of a single phonon would be around kT (25 meV compared to 3
>> eV for a blue photon), so you need a lot of electron-phonon
>> interaction to make a noticable shift.
>>
>> In case of the metal particle you will also have plasmon excitation.
>>
>> best wishes
>>
>> Andreas
>>
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: Johannes-P. Koch <[hidden email]>
>> To: [hidden email]
>> Sent: Thu, 28 Apr 2011 8:27
>> Subject: Re: same excitation and emission peaks
>>
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Think so too; if you measure something in a fluorimeter, you always
>> get a scattering "line" or peak (if looking at your spectra in 2D)!
>>
>>
>> Mark, could you comment on your phonon stuff?
>>
>> To my knowledge, phonons as such do not fluoresce; they do interact
>> with photons, i.e. you can generate a fluorescing photon by
>> annihilating a phonon or vice versa; still wherever you go, their is
>> some loss of energy, meaning that you cannot have exactly the same
>> peaks. - probabilistic or not!
>>
>> Johannes
>>
>> Am 28.04.2011 08:57, schrieb Sudipta Maiti:
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> are you not just looking at Rayleigh scattering?
>>> Sudipta
>>> On Thu, 28 Apr 2011 12:24:29 +0530, charu tanwar wrote
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> yes...that is what i also thought of. But this is the data we are
>>>> getting after repeatedly doing the experiment. Thanks
>>>>
>>>> CHARU TANWAR
>>>> Imaging Specialist
>>>> Advanced Instrumentation Research Facility
>>>> Jawaharlal Nehru University
>>>> New Delhi 110067
>>>> India.
>>>>
>>>> --- On Wed, 27/4/11, Jeffrey L. Travis<[hidden email]> wrote:
>>>>
>>>> From: Jeffrey L. Travis<[hidden email]>
>>>> Subject: Re: same excitation and emission peaks
>>>> To: [hidden email]
>>>> Date: Wednesday, 27 April, 2011, 7:33 PM
>>>>
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> Wouldn't that violate the Second Law?
>>>>
>>>> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
>>>>> *****
>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>> *****
>>>>>
>>>>> Dear List
>>>>>
>>>>> Not a direct confocal related query.
>>>>> Anyone please let me know whether any metallic nanoparticle with a
>>> definite size
>>>>> can have the same emission peak as its excitation peak???
>>>>>
>>>>> Thanks in advance
>>>>>
>>>>> Charu Tanwar
>>>>> Imaging Specialist
>>>>> Advanced Instrumentation Research Facility
>>>>> Jawaharlal Nehru University
>>>>> New Delhi
>>>>> India.
>>>>>
>>>>>
>>>
>>>
>>> Dr. Sudipta Maiti
>>> Associate Professor
>>> Dept. of Chemical Sciences
>>> Tata Institute of Fundamental Research
>>> Homi Bhabha Raod, Colaba, Mumbai 400005
>>> Ph. 91-22-2278-2716 / 2539
>>> Fax: 91-22-2280-4610
>>> alternate e-mail: [hidden email]
>>> url: biophotonics.wetpaint.com
>>>
>>
>> -- Mag. Johannes-P. KOCH
>> Department of Biochemistry and Cell Biology
>> MFPL, University of Vienna
>> Dr. Bohrgasse 9/5
>> A-1030 Vienna
>> Austria
>>
>> phone: 0043 1 4277 52809
>> fax: 0043 1 4277 9528
>>
>> mail to: [hidden email]
>>
>>
>>

Kurt Thorn

Re: same excitation and emission peaks

In reply to this post by S. Brunet

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

I would bet that both the 350 and 700 nm peaks are due to scattering.
You can easily check if the 700nm peak is due to scattering by putting a
UV-blocking longpass filter on the detection arm of the fluorimeter.

On 4/28/2011 8:23 AM, S. Brunet wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Hi,
> Is your emission peak at 700nm from excitation at 350nm?
> If so, did you verify that it is not due to 2nd order diffraction of 350nm from
> the emission monochromator?
> Bye,
> Sophie
> ____________________________________________________
> Sophie M. K. Brunet, Ph. D.
> Research Officer
> Optical Spectroscopy, Laser Systems and Applications
> [hidden email]
> 306-966-1719 (office) 306-966-1702 (fax)
> ____________________________________________________
> Saskatchewan Structural Sciences Centre
> University of Saskatchewan
> Thorvaldson Bldg.
> 110 Science Place
> Saskatoon, Sk S7N 5C9
> ____________________________________________________
>
>
> Quoting charu tanwar<[hidden email]>:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Dear Michael
>>
>> We got the excitation peak and emission peak data for these nanoparticles
>> from flourimeter (we scanned the particles in the range 200nm - 700nm and we
>> got one excitation peak at 350nm. Subsequently we got 2 emission peaks at
>> 350nm and 700nm). After confirming the excitation and emission spectra we
>> need to study theses particles insde cellualr system through confocal
>> microscopy.
>>
>> CHARU TANWAR
>> Imaging Specialist
>> Advanced Instrumentation Research Facility
>> Jawaharlal Nehru University
>> New Delhi 110067
>> India.
>>
>> --- On Wed, 27/4/11, Cammer, Michael<[hidden email]> wrote:
>>
>>
>> From: Cammer, Michael<[hidden email]>
>> Subject: Re: same excitation and emission peaks
>> To: [hidden email]
>> Date: Wednesday, 27 April, 2011, 7:31 PM
>>
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Are you seeing reflectance? We used to use the confocal in reflectance mode
>> to look at lead ATPase reaction product in liver and nickle enhanced gold
>> immuno.
>>
>> _________________________________________
>> Michael Cammer, Assistant Research Scientist
>> Skirball Institute of Biomolecular Medicine
>> Lab: (212) 263-3208 Cell: (914) 309-3270
>>
>> ________________________________________
>> From: Confocal Microscopy List [[hidden email]] On Behalf
>> Of Charu Tanwar [[hidden email]]
>> Sent: Wednesday, April 27, 2011 9:59 AM
>> To: [hidden email]
>> Subject: same excitation and emission peaks
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Dear List
>>
>> Not a direct confocal related query.
>> Anyone please let me know whether any metallic nanoparticle with a definite
>> size
>> can have the same emission peak as its excitation peak???
>>
>> Thanks in advance
>>
>> Charu Tanwar
>> Imaging Specialist
>> Advanced Instrumentation Research Facility
>> Jawaharlal Nehru University
>> New Delhi
>> India.
>>
>> ------------------------------------------------------------
>> This email message, including any attachments, is for the sole use of the
>> intended recipient(s) and may contain information that is proprietary,
>> confidential, and exempt from disclosure under applicable law. Any
>> unauthorized review, use, disclosure, or distribution is prohibited. If you
>> have received this email in error please notify the sender by return email
>> and delete the original message. Please note, the recipient should check this
>> email and any attachments for the presence of viruses. The organization
>> accepts no liability for any damage caused by any virus transmitted by this
>> email.
>> =================================
>>

Craig Brideau

Re: same excitation and emission peaks

In reply to this post by Mark Cannell

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Is that the stuff they use on certain IR detector cards? I have a type that
absorbs NIR and emits in the green. It doesn't require charging like the
other types (luminescent) so I always assumed it was some sort of
anti-stokes material.

Craig

On Thu, Apr 28, 2011 at 9:54 AM, Mark Cannell <[hidden email]>wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Yes:
> "When a system (be it a molecule or atom) absorbs a photon, it gains energy
> and enters an excited state. One way for the system to relax is to emit a
> photon, thus losing its energy (another method would be the loss of heat
> energy). When the emitted photon has less energy than the absorbed photon,
> this energy difference is the Stokes shift. If the emitted photon has more
> energy, the energy difference is called an anti-Stokes shift;[3] this extra
> energy comes from dissipation of thermal phonons in a crystal lattice,
> cooling the crystal in the process. Yttrium oxysulfidedoped with gadolinium
> oxysulfide is a common industrial anti-Stokes pigment, absorbing in the
> near-infrared and emitting in the visible portion of the spectrum."
> http://en.wikipedia.org/wiki/Stokes_shift
>
> Hope this helps, Mark
>
>
>
> On 29/04/2011, at 2:10 AM, Coutu, Cathy wrote:
>
> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Sorry, but I'm not familiar with an "antistokes shift". Would that be an
>> emission with a shorter wavelength than the excitation???
>>
>> Cathy
>>
>> Cathy Coutu, M. Sc.
>> Technician / Technicienne
>> Genomics, Bioinformatics, and other Bioinformation / Génomique,
>> Bioinformatique et Bioinformation
>> Agriculture and Agri-Food Canada/Agriculture et Agroalimentaire Canada
>> 107 Science place / 107 Place Science
>> Saskatoon, Saskatchewan / Saskatoon (Saskatchewan)
>> S7N 0X2
>> [hidden email]
>> Telephone/Téléphone: 306-956-2801
>> Facsimile/Télécopieur: 306-956-7247
>> Teletypewriter | Téléimprimeur 613-773-2600
>> Government of Canada | Gouvernement du Canada
>>
>> -----Original Message-----
>> From: Confocal Microscopy List [mailto:[hidden email]]
>> On Behalf Of Mark Cannell
>> Sent: April-28-11 4:43 AM
>> To: [hidden email]
>> Subject: Re: same excitation and emission peaks
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Quite so. But in this case he's not looking for an antistokes shift
>> just re-emission of the same apparent energy. It's the lower
>> probability of re-emission at this wavelength that prevents violation
>> of the second law.
>>
>> Cheers
>>
>> On 28/04/2011, at 10:30 PM, Andreas Bruckbauer wrote:
>>
>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>>
>>>
>>> To distinguish between Rayleigh or Mie scattering ('reflection') and
>>> photoluminescence you would need to measure time resolved, see e.g.
>>> G. Plesson et al. PHYSICAL REVIEW B 70, 205424 (2004). What you
>>> measure is most likely the excitation light, but you could try to
>>> vary the with of the excitation line if this is possible in your
>>> instrument and see if the peak varies accordingly.
>>>
>>> I think what Mark meant was the interaction of the excited electron
>>> with phonons, usually the energy is dissipated as phonons but you
>>> could also have phonons transferring energy to the electron in which
>>> case it would gain energy from the phonon. If it does not relax
>>> further and goes back into the ground state by emitting a photon,
>>> you will get anti stokes fluorescence. At room temperature the
>>> energy of a single phonon would be around kT (25 meV compared to 3
>>> eV for a blue photon), so you need a lot of electron-phonon
>>> interaction to make a noticable shift.
>>>
>>> In case of the metal particle you will also have plasmon excitation.
>>>
>>> best wishes
>>>
>>> Andreas
>>>
>>>
>>>
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: Johannes-P. Koch <[hidden email]>
>>> To: [hidden email]
>>> Sent: Thu, 28 Apr 2011 8:27
>>> Subject: Re: same excitation and emission peaks
>>>
>>>
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Think so too; if you measure something in a fluorimeter, you always
>>> get a scattering "line" or peak (if looking at your spectra in 2D)!
>>>
>>>
>>> Mark, could you comment on your phonon stuff?
>>>
>>> To my knowledge, phonons as such do not fluoresce; they do interact
>>> with photons, i.e. you can generate a fluorescing photon by
>>> annihilating a phonon or vice versa; still wherever you go, their is
>>> some loss of energy, meaning that you cannot have exactly the same
>>> peaks. - probabilistic or not!
>>>
>>> Johannes
>>>
>>> Am 28.04.2011 08:57, schrieb Sudipta Maiti:
>>>
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> are you not just looking at Rayleigh scattering?
>>>> Sudipta
>>>> On Thu, 28 Apr 2011 12:24:29 +0530, charu tanwar wrote
>>>>
>>>>> *****
>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>> *****
>>>>>
>>>>> yes...that is what i also thought of. But this is the data we are
>>>>> getting after repeatedly doing the experiment. Thanks
>>>>>
>>>>> CHARU TANWAR
>>>>> Imaging Specialist
>>>>> Advanced Instrumentation Research Facility
>>>>> Jawaharlal Nehru University
>>>>> New Delhi 110067
>>>>> India.
>>>>>
>>>>> --- On Wed, 27/4/11, Jeffrey L. Travis<[hidden email]> wrote:
>>>>>
>>>>> From: Jeffrey L. Travis<[hidden email]>
>>>>> Subject: Re: same excitation and emission peaks
>>>>> To: [hidden email]
>>>>> Date: Wednesday, 27 April, 2011, 7:33 PM
>>>>>
>>>>> *****
>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>> *****
>>>>>
>>>>> Wouldn't that violate the Second Law?
>>>>>
>>>>> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
>>>>>
>>>>>> *****
>>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>>> *****
>>>>>>
>>>>>> Dear List
>>>>>>
>>>>>> Not a direct confocal related query.
>>>>>> Anyone please let me know whether any metallic nanoparticle with a
>>>>>>
>>>>> definite size
>>>>
>>>>> can have the same emission peak as its excitation peak???
>>>>>>
>>>>>> Thanks in advance
>>>>>>
>>>>>> Charu Tanwar
>>>>>> Imaging Specialist
>>>>>> Advanced Instrumentation Research Facility
>>>>>> Jawaharlal Nehru University
>>>>>> New Delhi
>>>>>> India.
>>>>>>
>>>>>>
>>>>>>
>>>>
>>>> Dr. Sudipta Maiti
>>>> Associate Professor
>>>> Dept. of Chemical Sciences
>>>> Tata Institute of Fundamental Research
>>>> Homi Bhabha Raod, Colaba, Mumbai 400005
>>>> Ph. 91-22-2278-2716 / 2539
>>>> Fax: 91-22-2280-4610
>>>> alternate e-mail: [hidden email]
>>>> url: biophotonics.wetpaint.com
>>>>
>>>>
>>> -- Mag. Johannes-P. KOCHDepartment of Biochemistry and Cell Biology
>>>
>>> MFPL, University of Vienna
>>> Dr. Bohrgasse 9/5
>>> A-1030 Vienna
>>> Austria
>>>
>>> phone: 0043 1 4277 52809
>>> fax: 0043 1 4277 9528
>>>
>>> mail to: [hidden email]
>>>
>>>
>>>
>>>

Mark Cannell

Re: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

It could be but I don't know, what does the manufacturer say?

Mark

On 29/04/2011, at 8:08 AM, Craig Brideau wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> Is that the stuff they use on certain IR detector cards? I have a
> type that
> absorbs NIR and emits in the green. It doesn't require charging
> like the
> other types (luminescent) so I always assumed it was some sort of
> anti-stokes material.
>
> Craig
>
>
> On Thu, Apr 28, 2011 at 9:54 AM, Mark Cannell <[hidden email]
> >wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Yes:
>> "When a system (be it a molecule or atom) absorbs a photon, it
>> gains energy
>> and enters an excited state. One way for the system to relax is to
>> emit a
>> photon, thus losing its energy (another method would be the loss of
>> heat
>> energy). When the emitted photon has less energy than the absorbed
>> photon,
>> this energy difference is the Stokes shift. If the emitted photon
>> has more
>> energy, the energy difference is called an anti-Stokes shift;[3]
>> this extra
>> energy comes from dissipation of thermal phonons in a crystal
>> lattice,
>> cooling the crystal in the process. Yttrium oxysulfidedoped with
>> gadolinium
>> oxysulfide is a common industrial anti-Stokes pigment, absorbing in
>> the
>> near-infrared and emitting in the visible portion of the spectrum."
>> http://en.wikipedia.org/wiki/Stokes_shift
>>
>> Hope this helps, Mark
>>
>>
>>
>> On 29/04/2011, at 2:10 AM, Coutu, Cathy wrote:
>>
>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Sorry, but I'm not familiar with an "antistokes shift". Would
>>> that be an
>>> emission with a shorter wavelength than the excitation???
>>>
>>> Cathy
>>>
>>> Cathy Coutu, M. Sc.
>>> Technician / Technicienne
>>> Genomics, Bioinformatics, and other Bioinformation / Génomique,
>>> Bioinformatique et Bioinformation
>>> Agriculture and Agri-Food Canada/Agriculture et Agroalimentaire
>>> Canada
>>> 107 Science place / 107 Place Science
>>> Saskatoon, Saskatchewan / Saskatoon (Saskatchewan)
>>> S7N 0X2
>>> [hidden email]
>>> Telephone/Téléphone: 306-956-2801
>>> Facsimile/Télécopieur: 306-956-7247
>>> Teletypewriter | Téléimprimeur 613-773-2600
>>> Government of Canada | Gouvernement du Canada
>>>
>>> -----Original Message-----
>>> From: Confocal Microscopy List [mailto:[hidden email]
>>> ]
>>> On Behalf Of Mark Cannell
>>> Sent: April-28-11 4:43 AM
>>> To: [hidden email]
>>> Subject: Re: same excitation and emission peaks
>>>
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Quite so. But in this case he's not looking for an antistokes shift
>>> just re-emission of the same apparent energy. It's the lower
>>> probability of re-emission at this wavelength that prevents
>>> violation
>>> of the second law.
>>>
>>> Cheers
>>>
>>> On 28/04/2011, at 10:30 PM, Andreas Bruckbauer wrote:
>>>
>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>>
>>>>
>>>> To distinguish between Rayleigh or Mie scattering ('reflection')
>>>> and
>>>> photoluminescence you would need to measure time resolved, see e.g.
>>>> G. Plesson et al. PHYSICAL REVIEW B 70, 205424 (2004). What you
>>>> measure is most likely the excitation light, but you could try to
>>>> vary the with of the excitation line if this is possible in your
>>>> instrument and see if the peak varies accordingly.
>>>>
>>>> I think what Mark meant was the interaction of the excited electron
>>>> with phonons, usually the energy is dissipated as phonons but you
>>>> could also have phonons transferring energy to the electron in
>>>> which
>>>> case it would gain energy from the phonon. If it does not relax
>>>> further and goes back into the ground state by emitting a photon,
>>>> you will get anti stokes fluorescence. At room temperature the
>>>> energy of a single phonon would be around kT (25 meV compared to 3
>>>> eV for a blue photon), so you need a lot of electron-phonon
>>>> interaction to make a noticable shift.
>>>>
>>>> In case of the metal particle you will also have plasmon
>>>> excitation.
>>>>
>>>> best wishes
>>>>
>>>> Andreas
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: Johannes-P. Koch <[hidden email]>
>>>> To: [hidden email]
>>>> Sent: Thu, 28 Apr 2011 8:27
>>>> Subject: Re: same excitation and emission peaks
>>>>
>>>>
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> Think so too; if you measure something in a fluorimeter, you always
>>>> get a scattering "line" or peak (if looking at your spectra in 2D)!
>>>>
>>>>
>>>> Mark, could you comment on your phonon stuff?
>>>>
>>>> To my knowledge, phonons as such do not fluoresce; they do interact
>>>> with photons, i.e. you can generate a fluorescing photon by
>>>> annihilating a phonon or vice versa; still wherever you go, their
>>>> is
>>>> some loss of energy, meaning that you cannot have exactly the same
>>>> peaks. - probabilistic or not!
>>>>
>>>> Johannes
>>>>
>>>> Am 28.04.2011 08:57, schrieb Sudipta Maiti:
>>>>
>>>>> *****
>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>> *****
>>>>>
>>>>> are you not just looking at Rayleigh scattering?
>>>>> Sudipta
>>>>> On Thu, 28 Apr 2011 12:24:29 +0530, charu tanwar wrote
>>>>>
>>>>>> *****
>>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>>> *****
>>>>>>
>>>>>> yes...that is what i also thought of. But this is the data we are
>>>>>> getting after repeatedly doing the experiment. Thanks
>>>>>>
>>>>>> CHARU TANWAR
>>>>>> Imaging Specialist
>>>>>> Advanced Instrumentation Research Facility
>>>>>> Jawaharlal Nehru University
>>>>>> New Delhi 110067
>>>>>> India.
>>>>>>
>>>>>> --- On Wed, 27/4/11, Jeffrey L. Travis<[hidden email]> wrote:
>>>>>>
>>>>>> From: Jeffrey L. Travis<[hidden email]>
>>>>>> Subject: Re: same excitation and emission peaks
>>>>>> To: [hidden email]
>>>>>> Date: Wednesday, 27 April, 2011, 7:33 PM
>>>>>>
>>>>>> *****
>>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>>> *****
>>>>>>
>>>>>> Wouldn't that violate the Second Law?
>>>>>>
>>>>>> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
>>>>>>
>>>>>>> *****
>>>>>>> To join, leave or search the confocal microscopy listserv, go
>>>>>>> to:
>>>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>>>> *****
>>>>>>>
>>>>>>> Dear List
>>>>>>>
>>>>>>> Not a direct confocal related query.
>>>>>>> Anyone please let me know whether any metallic nanoparticle
>>>>>>> with a
>>>>>>>
>>>>>> definite size
>>>>>
>>>>>> can have the same emission peak as its excitation peak???
>>>>>>>
>>>>>>> Thanks in advance
>>>>>>>
>>>>>>> Charu Tanwar
>>>>>>> Imaging Specialist
>>>>>>> Advanced Instrumentation Research Facility
>>>>>>> Jawaharlal Nehru University
>>>>>>> New Delhi
>>>>>>> India.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>
>>>>> Dr. Sudipta Maiti
>>>>> Associate Professor
>>>>> Dept. of Chemical Sciences
>>>>> Tata Institute of Fundamental Research
>>>>> Homi Bhabha Raod, Colaba, Mumbai 400005
>>>>> Ph. 91-22-2278-2716 / 2539
>>>>> Fax: 91-22-2280-4610
>>>>> alternate e-mail: [hidden email]
>>>>> url: biophotonics.wetpaint.com
>>>>>
>>>>>
>>>> -- Mag. Johannes-P. KOCHDepartment of Biochemistry and Cell Biology
>>>>
>>>> MFPL, University of Vienna
>>>> Dr. Bohrgasse 9/5
>>>> A-1030 Vienna
>>>> Austria
>>>>
>>>> phone: 0043 1 4277 52809
>>>> fax: 0043 1 4277 9528
>>>>
>>>> mail to: [hidden email]
>>>>
>>>>
>>>>
>>>>

Craig Brideau

Re: same excitation and emission peaks

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

The most I've ever heard is 'an anti-stokes material' without them going
into further detail. That's why I was curious.

Craig

On Thu, Apr 28, 2011 at 2:12 PM, Mark Cannell <[hidden email]>wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> It could be but I don't know, what does the manufacturer say?
>
> Mark
>
>
> On 29/04/2011, at 8:08 AM, Craig Brideau wrote:
>
> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>>
>> Is that the stuff they use on certain IR detector cards? I have a type
>> that
>> absorbs NIR and emits in the green. It doesn't require charging like the
>> other types (luminescent) so I always assumed it was some sort of
>> anti-stokes material.
>>
>> Craig
>>
>>
>> On Thu, Apr 28, 2011 at 9:54 AM, Mark Cannell <[hidden email]
>> >wrote:
>>
>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>> *****
>>>
>>> Yes:
>>> "When a system (be it a molecule or atom) absorbs a photon, it gains
>>> energy
>>> and enters an excited state. One way for the system to relax is to emit a
>>> photon, thus losing its energy (another method would be the loss of heat
>>> energy). When the emitted photon has less energy than the absorbed
>>> photon,
>>> this energy difference is the Stokes shift. If the emitted photon has
>>> more
>>> energy, the energy difference is called an anti-Stokes shift;[3] this
>>> extra
>>> energy comes from dissipation of thermal phonons in a crystal lattice,
>>> cooling the crystal in the process. Yttrium oxysulfidedoped with
>>> gadolinium
>>> oxysulfide is a common industrial anti-Stokes pigment, absorbing in the
>>> near-infrared and emitting in the visible portion of the spectrum."
>>> http://en.wikipedia.org/wiki/Stokes_shift
>>>
>>> Hope this helps, Mark
>>>
>>>
>>>
>>> On 29/04/2011, at 2:10 AM, Coutu, Cathy wrote:
>>>
>>> *****
>>>
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> Sorry, but I'm not familiar with an "antistokes shift". Would that be
>>>> an
>>>> emission with a shorter wavelength than the excitation???
>>>>
>>>> Cathy
>>>>
>>>> Cathy Coutu, M. Sc.
>>>> Technician / Technicienne
>>>> Genomics, Bioinformatics, and other Bioinformation / Génomique,
>>>> Bioinformatique et Bioinformation
>>>> Agriculture and Agri-Food Canada/Agriculture et Agroalimentaire Canada
>>>> 107 Science place / 107 Place Science
>>>> Saskatoon, Saskatchewan / Saskatoon (Saskatchewan)
>>>> S7N 0X2
>>>> [hidden email]
>>>> Telephone/Téléphone: 306-956-2801
>>>> Facsimile/Télécopieur: 306-956-7247
>>>> Teletypewriter | Téléimprimeur 613-773-2600
>>>> Government of Canada | Gouvernement du Canada
>>>>
>>>> -----Original Message-----
>>>> From: Confocal Microscopy List [mailto:[hidden email]
>>>> ]
>>>> On Behalf Of Mark Cannell
>>>> Sent: April-28-11 4:43 AM
>>>> To: [hidden email]
>>>> Subject: Re: same excitation and emission peaks
>>>>
>>>> *****
>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>> *****
>>>>
>>>> Quite so. But in this case he's not looking for an antistokes shift
>>>> just re-emission of the same apparent energy. It's the lower
>>>> probability of re-emission at this wavelength that prevents violation
>>>> of the second law.
>>>>
>>>> Cheers
>>>>
>>>> On 28/04/2011, at 10:30 PM, Andreas Bruckbauer wrote:
>>>>
>>>> *****
>>>>
>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>> *****
>>>>>
>>>>>
>>>>>
>>>>> To distinguish between Rayleigh or Mie scattering ('reflection') and
>>>>> photoluminescence you would need to measure time resolved, see e.g.
>>>>> G. Plesson et al. PHYSICAL REVIEW B 70, 205424 (2004). What you
>>>>> measure is most likely the excitation light, but you could try to
>>>>> vary the with of the excitation line if this is possible in your
>>>>> instrument and see if the peak varies accordingly.
>>>>>
>>>>> I think what Mark meant was the interaction of the excited electron
>>>>> with phonons, usually the energy is dissipated as phonons but you
>>>>> could also have phonons transferring energy to the electron in which
>>>>> case it would gain energy from the phonon. If it does not relax
>>>>> further and goes back into the ground state by emitting a photon,
>>>>> you will get anti stokes fluorescence. At room temperature the
>>>>> energy of a single phonon would be around kT (25 meV compared to 3
>>>>> eV for a blue photon), so you need a lot of electron-phonon
>>>>> interaction to make a noticable shift.
>>>>>
>>>>> In case of the metal particle you will also have plasmon excitation.
>>>>>
>>>>> best wishes
>>>>>
>>>>> Andreas
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> -----Original Message-----
>>>>> From: Johannes-P. Koch <[hidden email]>
>>>>> To: [hidden email]
>>>>> Sent: Thu, 28 Apr 2011 8:27
>>>>> Subject: Re: same excitation and emission peaks
>>>>>
>>>>>
>>>>> *****
>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>> *****
>>>>>
>>>>> Think so too; if you measure something in a fluorimeter, you always
>>>>> get a scattering "line" or peak (if looking at your spectra in 2D)!
>>>>>
>>>>>
>>>>> Mark, could you comment on your phonon stuff?
>>>>>
>>>>> To my knowledge, phonons as such do not fluoresce; they do interact
>>>>> with photons, i.e. you can generate a fluorescing photon by
>>>>> annihilating a phonon or vice versa; still wherever you go, their is
>>>>> some loss of energy, meaning that you cannot have exactly the same
>>>>> peaks. - probabilistic or not!
>>>>>
>>>>> Johannes
>>>>>
>>>>> Am 28.04.2011 08:57, schrieb Sudipta Maiti:
>>>>>
>>>>> *****
>>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>>> *****
>>>>>>
>>>>>> are you not just looking at Rayleigh scattering?
>>>>>> Sudipta
>>>>>> On Thu, 28 Apr 2011 12:24:29 +0530, charu tanwar wrote
>>>>>>
>>>>>> *****
>>>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>>>> *****
>>>>>>>
>>>>>>> yes...that is what i also thought of. But this is the data we are
>>>>>>> getting after repeatedly doing the experiment. Thanks
>>>>>>>
>>>>>>> CHARU TANWAR
>>>>>>> Imaging Specialist
>>>>>>> Advanced Instrumentation Research Facility
>>>>>>> Jawaharlal Nehru University
>>>>>>> New Delhi 110067
>>>>>>> India.
>>>>>>>
>>>>>>> --- On Wed, 27/4/11, Jeffrey L. Travis<[hidden email]> wrote:
>>>>>>>
>>>>>>> From: Jeffrey L. Travis<[hidden email]>
>>>>>>> Subject: Re: same excitation and emission peaks
>>>>>>> To: [hidden email]
>>>>>>> Date: Wednesday, 27 April, 2011, 7:33 PM
>>>>>>>
>>>>>>> *****
>>>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>>>> *****
>>>>>>>
>>>>>>> Wouldn't that violate the Second Law?
>>>>>>>
>>>>>>> On 4/27/2011 9:59 AM, Charu Tanwar wrote:
>>>>>>>
>>>>>>> *****
>>>>>>>> To join, leave or search the confocal microscopy listserv, go to:
>>>>>>>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>>>>>>>> *****
>>>>>>>>
>>>>>>>> Dear List
>>>>>>>>
>>>>>>>> Not a direct confocal related query.
>>>>>>>> Anyone please let me know whether any metallic nanoparticle with a
>>>>>>>>
>>>>>>>> definite size
>>>>>>>
>>>>>>
>>>>>> can have the same emission peak as its excitation peak???
>>>>>>>
>>>>>>>>
>>>>>>>> Thanks in advance
>>>>>>>>
>>>>>>>> Charu Tanwar
>>>>>>>> Imaging Specialist
>>>>>>>> Advanced Instrumentation Research Facility
>>>>>>>> Jawaharlal Nehru University
>>>>>>>> New Delhi
>>>>>>>> India.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>> Dr. Sudipta Maiti
>>>>>> Associate Professor
>>>>>> Dept. of Chemical Sciences
>>>>>> Tata Institute of Fundamental Research
>>>>>> Homi Bhabha Raod, Colaba, Mumbai 400005
>>>>>> Ph. 91-22-2278-2716 / 2539
>>>>>> Fax: 91-22-2280-4610
>>>>>> alternate e-mail: [hidden email]
>>>>>> url: biophotonics.wetpaint.com
>>>>>>
>>>>>>
>>>>>> -- Mag. Johannes-P. KOCHDepartment of Biochemistry and Cell Biology
>>>>>
>>>>> MFPL, University of Vienna
>>>>> Dr. Bohrgasse 9/5
>>>>> A-1030 Vienna
>>>>> Austria
>>>>>
>>>>> phone: 0043 1 4277 52809
>>>>> fax: 0043 1 4277 9528
>>>>>
>>>>> mail to: [hidden email]
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>

Jeremy Adler-4

Re: same excitation and emission peaks

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http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

what happens when you shift the excitation wavelength ?