808nm optics. collimators, cylindrical lenses

[atomd]

Hi,
I'm basically trying to collimate and shape a 808nm beam to pump Nd:YAG, but all quotes for optics I got were outrageous.

[Laser57]

This seller on ebay might have them, but not listed. He had some fiber to convex 808 nm lenses with AR coating in the past and not expensive, as they go. You could remove the fiber, or leave it on to interface to a FAP. What kind of laser is your 808 nm coming out of? Simple diode, or? What are you seeking, double convex, convex-flat (plano convex) and focal length desired? Edit: If you can't find something suitable anywhere PM me, I might have something.

https://www.ebay.com/str/3dphotonicsplus

[atomd]

This seller on ebay might have them, but not listed. He had some fiber to convex 808 nm lenses with AR coating in the past and not expensive, as they go. You could remove the fiber, or leave it on to interface to a FAP. What kind of laser is your 808 nm coming out of? Simple diode, or? What are you seeking, double convex, convex-flat (plano convex) and focal length desired? Edit: If you can't find something suitable anywhere PM me, I might have something.

https://www.ebay.com/str/3dphotonicsplus

I'm primarily looking for cylindrical lenses to build a telescope to expand the beams from individual laser diodes. For that, I need short concave lens and longer convex lens, for eg. -4mm and +40mm. Additionally, I need (preferably M9) collimators for the diodes, but I found a few options here.

[Laser57]

Is this in addition to your YAG project to focus 808 nm into the crystal? Beam expanders are easy, you don't necessarily need an AR coated lens for 808 nm as an output expander, it won't be as efficient, but not that much loss, not needed for a pointer output unless your diode is sensitive to reflections off the lens. So, are you doing two projects, one is to focus 808 nm into a crystal and another set to expand the beam to reduce divergence, or?

Are building a DPSS and want to expand the output?

[kecked]

Is this in addition to your YAG project to focus 808 nm into the crystal? Beam expanders are easy, you don't necessarily need an AR coated lens for 808 nm as an output expander, it won't be as efficient, but not that much loss, not needed for a pointer output unless your diode is sensitive to reflections off the lens. So, are you doing two projects, one is to focus 808 nm into a crystal and another set to expand the beam to reduce divergence, or?

Are building a DPSS and want to expand the output?

go on thorlabs and pick the exact optics you want and post here or LP.

[Laser57]

Last I heard the ebay seller I linked to thinks he has what he needs.

On another subject, highjacking this thread for only a short while, does anyone know what the SHG output wavelength would be for a KTP crystal which is cut for a 47.5 degree phase angle when pumped with 1064 nm, for either type 1 or type 2? The chat gpt I am asking this question of outputs different answers to the same question!

[atomd]

Last I heard the ebay seller I linked to thinks he has what he needs.

On another subject, highjacking this thread for only a short while, does anyone know what the SHG output wavelength would be for a KTP crystal which is cut for a 47.5 degree phase angle when pumped with 1064 nm, for either type 1 or type 2? The chat gpt I am asking this question of outputs different answers to the same question!

And that's because GPTchat is stupid! SHG as the name suggests will always output 532nm from 1064nm, but if phase matching condition is not matched the output power will be very, very low. There's another option - DFG which would downconvert signal to MIR signal and idler but without extreme input powers it won't work without resonant cavity. There's a really nice calculator for playing around with nonlinear processes, though for some reason it doesn't support KTP: https://toolbox.lightcon.com/tools/SFG

go on thorlabs and pick the exact optics you want and post here or LP.

Sure. Example pair of products that'd be of interest to me:
LK1597L2-B & LJ1402L2-B

Is this in addition to your YAG project to focus 808 nm into the crystal? Beam expanders are easy, you don't necessarily need an AR coated lens for 808 nm as an output expander, it won't be as efficient, but not that much loss, not needed for a pointer output unless your diode is sensitive to reflections off the lens. So, are you doing two projects, one is to focus 808 nm into a crystal and another set to expand the beam to reduce divergence, or?

Are building a DPSS and want to expand the output?

Actually, it's the same project. In order to better much pump diode to cavity, I need to expand the beam in one axis before collimating it onto the crystal. I know the lenses don't have to be coated, but uncoated lenses make me loose 16% of the light, which forces me to add more pump diodes, reduces small signal gain, ...

[Laser57]

Yep, it's confirmed, chatgpt is stupid. I cannot rely on them for good answers. For my own projects, I don't want to use a lens which isn't AR coated either, but difficult to find what I need with coatings. I had to special order some OC mirrors made with the coatings I needed once, cost me near 2,000 dollars.

[atomd]

Yep, it's confirmed, chatgpt is stupid. I cannot rely on them for good answers. For my own projects, I don't want to use a lens which isn't AR coated either, but difficult to find what I need with coatings. I had to special order some OC mirrors made with the coatings I needed once, cost me near 2,000 dollars.

Could you share what did you order (roughly, exact specs aren't critical), where and for how much? I'm trying to come up with open source manufacturer DB.

[Laser57]

Could you share what did you order (roughly, exact specs aren't critical), where and for how much? I'm trying to come up with open source manufacturer DB.

They were OC's for a 444 nm pumped cavity to PR:YLF crystal to produce 607 nm, a company in Lithuania made them for me, I need to dig out the info to give you a name, escapes me right now. Edit: Optogama. I need to find the invoice, the email account I used in the past is now disabled, but I have the documentation somewhere in my storage room. The project was put on hold after one member of a team of three completely dropped out of the project, even after I paid him to produce some sophisticated driver boards with display and control board, poof, gone. If I remember correctly, the good OC's were 150 dollars or so each, I bought some rejects for half that each, these were made to order.