http://confocal-microscopy-list.275.s1.nabble.com/2P-laser-coupled-to-a-DMD-tp7590172p7590204.html
The power requirement is more relevant if you want to hit multiple cells at a time. In general, an SLM-based approach is lossy, as you are working with the first order, while the majority of light will end up in the non-diffracted zero-order. I know users of commercial solutions who are firing 20 W of 1030 nm light into the microscope and getting 500 mW out of the objective.
Many of the red-shifted opsins will be efficiently excited by 1030 - 1064 nm. A wavelength range that has a wide selection of affordable lasers is available. If you have an Insight, I would try that first, though.
Dr. Christian Wilms / Research & Development Manager
Take a look at our NeuroWire blog to see our latest news, guides, videos and more.
> -----Original Message-----
> From: Gary Laevsky <
[hidden email]>
> Sent: 20 November 2019 14:06
> Subject: Re: 2P laser coupled to a DMD?
>
> *****
> To join, leave or search the confocal microscopy listserv, go to:
>
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy> Post images on
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> *****
>
> > Thank you all!
> >
> > From what I understand, this is totally doable. I'll need to use an
> > SLM as opposed to a DMD.
> >
> > Clarification and additional questions;
> >
> > This is for spatial non-linearity. I want to light up "a" cell in a
> > biofilm/embryo/tissue, at "depth," less than 100 um. I'm not going to
> > be able to do this with 1P, right? So this WILL limit the selection
> > of opsins. If I get something like an InSight, 1300 should get me to
> > the red-shifted? I just emailed Darcy:)
> >
> > I'm surprised about the power requirement. I would have thought low
> > power would be sufficient?
> >
> > I'm thinking I have two options; put the SLM between a scan head and
> > the scope, with divergent then collimating optics to the SLM, and park
> > the beam of the scan head on the SLM? Or, skip the scan head and
> > couple the laser/SLM directly to stand. The former will give me
> > additional capability, but I'm not sure if that light path is viable?
> >
> > Thank you ALL very much!
> >
> >
> >
> > On Wed, Nov 20, 2019 at 4:57 AM Christian Wilms <
> >
[hidden email]> wrote:
> >
> >> Hi Gary,
> >>
> >> As others have already said, a DMD won't easily get you the power
> >> levels that you require for 2P excitation of most optogenetic tools.
> >> LCoS SLMs are the tool of choice for this. Many commercial suppliers
> >> of multiphoton microscopes have licensed the technology and now sell
> >> such add-ons (or have them in development), so it might be worth
> >> asking the manufacturer of your system.
> >>
> >> If you are more the DIY type, have a look at the work by Volodymyr
> >> Nikolenko and Darcy Peterka from Rafael Yuste's lab at Columbia. This
> >> paper might be a good introduction:
> >>
https://doi.org/10.3389/neuro.04.005.2008> >>
> >> Darcy and his colleagues (among many others) are really helping push
> >> this technology and are just a couple of hours from you and are the
> >> holders of the main patent covering this technology.
> >>
> >> In addition to the actual SLM, if you want to target more than a few
> >> spots simultaneously, you should also be looking into suitable
> >> lasers, as the ones commonly used in multiphoton imaging tend not to
> >> hit the required parameters for most opsins.
> >>
> >> Best, Christian
> >>
> >> Dr. Christian Wilms / Research & Development Manager
> >>
[hidden email] / +44 (0)1825 749933
> >> www.scientifica.uk.com
> >>
> >> Take a look at our NeuroWire blog to see our latest news, guides,
> >> videos and more.
> >>
> >> > -----Original Message-----
> >> > From: Gary Laevsky <
[hidden email]>
> >> > Sent: 19 November 2019 20:33
> >> > Subject: 2P laser coupled to a DMD?
> >> >
> >> > *****
> >> > To join, leave or search the confocal microscopy listserv, go to:
> >> >
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy> >> > Post images on
http://www.imgur.com and include the link in your
> >> posting.
> >> > *****
> >> >
> >> > Hi All,
> >> >
> >> > I THINK this can be done? DMD that can handle high power and
> >> appropriate
> >> > reflective characteristics for the wavelength. Or could I do this
> >> > with
> >> an SLM?
> >> >
> >> > We're looking to do non-linear optogenetic switching.
> >> >
> >> > If this is simple, please be gentle. I'm a biologist ...:)
> >> >
> >> > If it is simple, can you please direct me to the appropriate vendor.
> >> >
> >> > Thanks in advance.
> >> >
> >> > --
> >> > Best,
> >> >
> >> > Gary Laevsky, Ph.D.
> >> > Director, Confocal Imaging Facility Nikon Center of Excellence
> >> > Co-Founder, North Atlantic Microscopy Society (NAMS)
> >> >
https://namsmicroscopy.com/ Dept. of Molecular Biology Washington Rd.
> >> > Princeton University
> >> > Princeton, New Jersey, 08544-1014
> >> > (O) 609 258 5432
> >> > (C) 508 507 1310
> >> >
> >> > North Atlantic Microscopy Society Spring Meeting at UPENN, April
> >> > 23,
> >> 2020.
> >>
> >
> >
> > --
> > Best,
> >
> > Gary Laevsky, Ph.D.
> > Director, Confocal Imaging Facility
> > Nikon Center of Excellence
> > Co-Founder, North Atlantic Microscopy Society (NAMS)
> >
https://namsmicroscopy.com/ Dept. of Molecular Biology Washington Rd.
> > Princeton University
> > Princeton, New Jersey, 08544-1014
> > (O) 609 258 5432
> > (C) 508 507 1310
> >
> > North Atlantic Microscopy Society Spring Meeting at UPENN, April 23, 2020.
> >
>
>
> --
> Best,
>
> Gary Laevsky, Ph.D.
> Director, Confocal Imaging Facility
> Nikon Center of Excellence
> Co-Founder, North Atlantic Microscopy Society (NAMS)
>
https://namsmicroscopy.com/ Dept. of Molecular Biology Washington Rd.
> Princeton University
> Princeton, New Jersey, 08544-1014
> (O) 609 258 5432
> (C) 508 507 1310
>
> North Atlantic Microscopy Society Spring Meeting at UPENN, April 23, 2020.