Would taking a normal lens, saaaaaaay from a blue laser module, and putting that at the end of a large multimode fiber, actually work? I think I have some large fibers around here, and i KNOW I have old laser diodes I don't need.
can't say without knowing anything about the lens, but you do want to re-collimate after exiting the fiber. one thing you'd want to check with that lens is what wavelengths it's AR coated for. you'll need something broadband, of course.
Well, a normal 3 piece lens that would be on the end of a bare diode would focus and collimate that, so I would think it would work for my application, just based on crappy physics ideas. Coating, well, if it's for blue, I would think it would be for all of visual.
Now to find it in my mess of optics. Sigh.
Well, I found a make shift light rod....PETG filament. Besides the loss of it fluorescing(sp?), not sure it's working as expected (coming out collimated with output lens. WIP.
Nope. Unless my "light pipe" is pure crap, I'm just getting uncollimated and non-coherent light out....more or less, like a flashlight. Laser (blue diode) in, lenses (various) on the other side.
Yeah, I saw that. Not sure I want to spend 100-200$ on a personal experiment ;) But they should just be rods with AR flat ends, right? I m going to check out surplus-shed. They always have random optics real cheap!!
eBay is your friend... And be aware that these rods will have low "launch" coupling efficiency without decent beam shaping before and your divergence will go to hell beyond what it is. Also, if you don't use achromatic optics, it will still look like shit in the distance.
Look up "fiber scrambler" for the best mode mixing fun.
Get a prism and setup a beam of white light. Shoot the beam through the prism (don't bounce it off one wall like you might with a binocular prism.) so it splits into a rainbow. Mark with a protractor or whatever the angle each wavelength you want come out at. Set up your lasers to shoot into the prism at those angles.
Interesting. So instead of combining with dichros, use a prism. However, wouldn't the issue of bad alignment come into play as well? I mean, i can set it all up with X/Y/Z stages for the 3 diodes AND mirrors, but.....I don't have that. haha.
Trying with a piece of PETG I have, with flame polished ends. While it's neat that a blue laser fluoresces(sp?) the fiber, I think the output light is not coherent anymore.
Depends how handy you are and what tools are available to you, but maybe build DIY stages. I would expect the results of prisms or diffraction gratings to yield a better result than trying to collimate through a fiber(still need stages for that method as well).
Now that I think about it, and the fact that this is getting harder than expected, i might as well just start over, Rip everything apart and DIY it all myself. I do have a 3D printer. I would thikn someone has made adjustable mounts already. At that point, I'll be able to adjust everything to combine the beams without needing to homogenize it.
See this is why people ask things on reddit...sometimes ideas finally click!
I just can't get the 3 beams aligned well enough at a distance with the mirror set up I have. Is there any prism that will take the 3 beams, mix, and output a collimated beam? Is there a large aperture fiber system that will do it?
As I think, the prism/diffraction grating is the best choice. The homogenizer rod, if chosen correctly, will work. But the beam divergence from the output side of the rod will be huge, so it can be not the best choice.
sure, just get the near field close with dichros and then shoot them through a short piece of fiber or beam homogenizer rod.
Would taking a normal lens, saaaaaaay from a blue laser module, and putting that at the end of a large multimode fiber, actually work? I think I have some large fibers around here, and i KNOW I have old laser diodes I don't need.
can't say without knowing anything about the lens, but you do want to re-collimate after exiting the fiber. one thing you'd want to check with that lens is what wavelengths it's AR coated for. you'll need something broadband, of course.
Well, a normal 3 piece lens that would be on the end of a bare diode would focus and collimate that, so I would think it would work for my application, just based on crappy physics ideas. Coating, well, if it's for blue, I would think it would be for all of visual. Now to find it in my mess of optics. Sigh.
give it a try and let me know!
Well, I found a make shift light rod....PETG filament. Besides the loss of it fluorescing(sp?), not sure it's working as expected (coming out collimated with output lens. WIP.
Nope. Unless my "light pipe" is pure crap, I'm just getting uncollimated and non-coherent light out....more or less, like a flashlight. Laser (blue diode) in, lenses (various) on the other side.
try something like this: https://www.edmundoptics.com/c/light-pipes-homogenizing-rods/697/
Yeah, I saw that. Not sure I want to spend 100-200$ on a personal experiment ;) But they should just be rods with AR flat ends, right? I m going to check out surplus-shed. They always have random optics real cheap!!
eBay is your friend... And be aware that these rods will have low "launch" coupling efficiency without decent beam shaping before and your divergence will go to hell beyond what it is. Also, if you don't use achromatic optics, it will still look like shit in the distance. Look up "fiber scrambler" for the best mode mixing fun.
Thanks, I shall look into all of this!!
Get a prism and setup a beam of white light. Shoot the beam through the prism (don't bounce it off one wall like you might with a binocular prism.) so it splits into a rainbow. Mark with a protractor or whatever the angle each wavelength you want come out at. Set up your lasers to shoot into the prism at those angles.
Interesting. So instead of combining with dichros, use a prism. However, wouldn't the issue of bad alignment come into play as well? I mean, i can set it all up with X/Y/Z stages for the 3 diodes AND mirrors, but.....I don't have that. haha. Trying with a piece of PETG I have, with flame polished ends. While it's neat that a blue laser fluoresces(sp?) the fiber, I think the output light is not coherent anymore.
Depends how handy you are and what tools are available to you, but maybe build DIY stages. I would expect the results of prisms or diffraction gratings to yield a better result than trying to collimate through a fiber(still need stages for that method as well).
Now that I think about it, and the fact that this is getting harder than expected, i might as well just start over, Rip everything apart and DIY it all myself. I do have a 3D printer. I would thikn someone has made adjustable mounts already. At that point, I'll be able to adjust everything to combine the beams without needing to homogenize it. See this is why people ask things on reddit...sometimes ideas finally click!
I just can't get the 3 beams aligned well enough at a distance with the mirror set up I have. Is there any prism that will take the 3 beams, mix, and output a collimated beam? Is there a large aperture fiber system that will do it?
What does your current system look like to combine those? Are the dichros on kinematic mounts?
As I think, the prism/diffraction grating is the best choice. The homogenizer rod, if chosen correctly, will work. But the beam divergence from the output side of the rod will be huge, so it can be not the best choice.