GRIN lens with diameter of 0.5 mm

[ramseya]

Hi everyone,

Has anyone successful used a 0.5 mm diameter GRIN lens with this system? What were the dimensions of the brass jacket you used. How much of the lens did you have going into the body of the scope? How much of the brass jacket protruded from the scope? We see that the thickness of the baseplate is about 1 mm so we were thinking of having 1 mm of the brass jacket protrude from the scope body and having 1 mm up in the scope body.

Thanks!

Austin

[Daniel Aharoni]

Hi Austin,
I just wanted to clarify one thing concerning the Miniscope and thinner GRIN lenses.

When using lenses thinner than 1.8mm in diameter you need to use a dual GRIN lens setup. This amounts to use a thin (0.5mm to 1mm diameter) relay GRIN lens in conjunction with a larger (1.8mm or 2mm diameter) objective GRIN lens. Take a look here, http://miniscope.org/index.php?title=Imaging_With_Thin_GRIN_Lenses, for more info.

[ramseya]

Hi Daniel,

What should I be careful of then, when using a relay lens of 0.5 mm diameter (I'm trying to order some now)? Do I need to worry about it's length or should I be able to focus the images by changing the distance between the two GRIN lenses?

Thanks,

Austin

[Daniel Aharoni]

Hi Austin,
While you will always be limited to a few hundred micrometers of imaging depth due to scattering in tissue, a relay lens in conjunction with the Miniscope will allow you to adjust the focal plane throughout this distance by either adjust the distance between the 2 GRIN lenses (when mounting the baseplate) as well as by adjusting the height of the CMOS sensor.

If ordering relay lenses from Inscopix, any of their standard relay lenses should work with our system. If ordering custom relay GRIN lenses you want to make sure the deepest plane you plan on imaging will form an intermediate image slightly above the relay lens.

[adavidson]

Hey Austin/Daniel- I am also interested in trying 0.5mm and 0.6mm diameter lenses for ventral hypothalamus. Needs to be ~8.5mm long.  Let me know if you find any success sourcing the correct lenses. So far Inscopix has turned me down. email me at adavidson@msm.edu.

[Daniel Aharoni]

Hi adavidson,
The "official" position from Inscopix is they will supply anyone with their standard relay GRIN lenses which includes their 0.5mm and 0.6mm lenses. Unfortunately it appears many labs are have difficulty getting Inscopix to respond to quote requests and stick to their official position.  I suggest keep trying to contact them including publicly messaging them on twitter.

We are working with GoFoton on making these lenses (currently we have great lenses from them down to 0.8mm in diameter). Hopefully they will have even thinner lenses working soon.

[adavidson]

Daniel - Can you give me details on the gofoton lenses (i.e. what are the options, costs, timeline and product #s)? I have ordered a few relay lenses from Inscopix to try, but want to identify other sources as well. 

[Daniel Aharoni]

Hi,
You can contact GoFoton directly and they should be able to answer all your questions. They are very familiar with the Miniscope project and should be able to help.

[adavidson]

I have done so. THANKS Daniel! THis resource in its entirety is amazing, and your responsiveness to our questions and issues is surprising and appreciated. Looking forward to meeting you at the April workshop. -Alec

[Lee Hyeonju]

Hi Alec,

Did you buy 0.5mm GRIN lens for deep brain region from Go!foton?
I contacted Go!foton yesterday, and they said 0.5mm lens was under test in UCLA.

[adavidson]

Not yet. I have  0.5mm lenses from Inscopix, so I haven't needed to order any from Gofoton. It is good to know that they are being tested though. Good to have more than 1 source.

[chase_clark]

Hi there,

Has there been any update on how well the 0.5mm lenses from Go!Foton are working? We'd be interested in using them if they're just as good as those from Inscopix/Grintech.

Chase