home build a laser combiner

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Tim zhang-2 Tim zhang-2
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home build a laser combiner

Has anyone ever built a laser combiner? Is it difficult? I
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Dear All,

Has anyone ever built a laser combiner? Is it difficult? I am thinking about doing it by myself. I looked a few systems and they don't look like very complicated. I think the most critical part is the AOTF modulator. But most commercial systems use products from other companies. So except for this, is there other tricky part? Any suggestions will be appreciated.

Tim


       
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John Oreopoulos John Oreopoulos
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Re: home build a laser combiner

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Hi Tim,

I've never built a full laser combiner, but you're right that the  
optics inside a laser combiner box are fairly simple. It's really just  
a bunch of dichroic mirrors, regular broadband mirrors, and glass  
wedges for small beam deviations. You can use simple shutters instead  
of an AOM if you're not concerned about speed. Coupling into a single  
mode fiber requires a lot of patience. Make sure all your lasers and  
mounts are fixed rigidly and positioned in a place where they won't be  
kicked or disturbed and make sure the mounts have the proper  
translating degrees of freedom (pitch, yaw, x, y, z, etc.). There are  
lots of companies that sell suitable optomechanical mounts that  
translate or rotate (Thorlabs and Newport come to mind). Choosing  
lasers is a whole other matter, and I'm not the best to give advice on  
this.
I have experience free-spacing (no optical fibers) laser beams into  
the back epifluoresence port of a microscope for wide field or TIRF  
imaging, and so I can give you more details about that if you like.  
The confocal will probably require a fiber if it's a commercial system  
you're modifying, and pointing stability and size of the beam diameter  
will be factors to consider. I once tried coupling a 532 nm laser  
pointer (for presentations) down our Olympus Fluoview 300 and was  
easily able to image fluorescent beads using this laser source. The  
laser pointer cost about $100.


John Oreopoulos, BSc,
Master's Candidate
University of Toronto
Institute For Biomaterials and Biomedical Engineering
Centre For Studies in Molecular Imaging

Tel: W:416-946-5022



Quoting Tim zhang <[hidden email]>:

> Has anyone ever built a laser combiner? Is it difficult? I
> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> Dear All,
>
> Has anyone ever built a laser combiner? Is it difficult? I am  
> thinking about doing it by myself. I looked a few systems and they  
> don't look like very complicated. I think the most critical part is  
> the AOTF modulator. But most commercial systems use products from  
> other companies. So except for this, is there other tricky part? Any  
>  suggestions will be appreciated.
>
> Tim
>
>
>
> ____________________________________________________________________________________
> Be a better Globetrotter. Get better travel answers from someone who  
>  knows. Yahoo! Answers - Check it out.
> http://answers.yahoo.com/dir/?link=list&sid=396545469
>
Craig Brideau Craig Brideau
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Re: home build a laser combiner

Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Depending on how quickly you need to adjust the laser power, a filter
wheel loaded with neutral density filters is much simpler than an AOM.
 You can even get software-controlled motorized wheels so you can run
it from within your imaging suite. Otherwise it's just a matter of
picking the right dichroics to combine the lasers.  One thing I would
caution is that some of the dichroics can be polarization sensitive,
so you may need a half-waveplate here or there to rotate the beam
polarizations for better throughput with the dichroics.

Craig
Kevin Braeckmans Kevin Braeckmans
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Re: home build a laser combiner

In reply to this post by Tim zhang-2
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Dear Tim,

Combining a few lasers is not difficult as you suggest - a lot of people are
doing this for custom built systems - although it requires some patience to
get a good collinear alignment of the laser beams. If you can do it on a
breadboard or optical table, all you need are some standard optical
components to mount the lasers, (dichroic) mirrors (two per laser beam!)
etc. I think you can build it at approx 60% of the price of a commercial
laser box, but of course it will take some time to set it up and it will
also take up more space.

Putting in an AOTF is also very easy (and not very expensive @ 2000 - 4000
euro!), just make sure you buy a good positioning system. I am using an AOTF
from AA Opto Electronic (www.a-a.fr) and a positioning system from New Focus
(www.newfocus.com). The AOTF can be controlled manually with a remote
control, although it can be easily controlled with a computer as well if you
do a little programming.

However, if you are considering buying a new commercial confocal system, I
would not recommend building the laser box yourself since the company will
probably give no support. Also the lasers and/or AOTF are controlled through
the vendor's hard- and software, so getting all parts to communicate
properly might be a very difficult, if not impossible, task if there is no
support ...  unless you have lots of free time to figure it all out ;-)

Hope this helps,

Best regards,

Kevin

Kevin Braeckmans, Ph.D.
Lab. General Biochemistry and Physical Pharmacy
Ghent University
Harelbekestraat 72
9000 Ghent
Belgium
Tel: +32 (0)9 264.80.78
Fax: +32 (0)9 264.81.89

> -----Oorspronkelijk bericht-----
> Van: Confocal Microscopy List [mailto:[hidden email]]
> Namens Tim zhang
> Verzonden: vrijdag 14 september 2007 22:31
> Aan: [hidden email]
> Onderwerp: home build a laser combiner
>
> Has anyone ever built a laser combiner? Is it difficult? I
> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> Dear All,
>
> Has anyone ever built a laser combiner? Is it difficult? I am thinking
> about doing it by myself. I looked a few systems and they don't look
> like very complicated. I think the most critical part is the AOTF
> modulator. But most commercial systems use products from other
> companies. So except for this, is there other tricky part? Any
> suggestions will be appreciated.
>
> Tim
>
>
>
> _______________________________________________________________________
> _____________
> Be a better Globetrotter. Get better travel answers from someone who
> knows. Yahoo! Answers - Check it out.
> http://answers.yahoo.com/dir/?link=list&sid=396545469