Search found 113 matches

by Luc
Fri Jul 19, 2024 6:02 pm
Forum: OpenRAMAN
Topic: Cheapest Fiber Optics Cable?
Replies: 3
Views: 16

Re: Cheapest Fiber Optics Cable?

For calibration, cheap PMMA fibers might do the trick. As always, it's a trial and error process but I don't see reason it wouldn't work. What I did in the past (for other projects) was to buy audio patches from store like Wal-Mart and to cut the end, print or machine a custom connector and glue it....
by Luc
Fri Jul 19, 2024 5:34 am
Forum: OpenRAMAN
Topic: Fiber Cable Setup?
Replies: 1
Views: 4

Re: Fiber Cable Setup?

Yes you definitely can :) it's just more expensive and you can't change easily the image size by moving the lens relative to the fiber
by Luc
Fri Jul 19, 2024 5:31 am
Forum: OpenRAMAN
Topic: Cheapest Fiber Optics Cable?
Replies: 3
Views: 16

Re: Cheapest Fiber Optics Cable?

In the past I used some cheap PMMA fibers for audio setups but they don't have SMA connectors. If you have a 3d printer you could work something out.

It should (IMHO) work for the calibration part.
by Luc
Mon Jul 15, 2024 5:35 am
Forum: OpenRAMAN
Topic: DJ532-40 Beam Diameter/Collimation
Replies: 1
Views: 121

Re: DJ532-40 Beam Diameter/Collimation

I tried but without much success. No idea what the beam waist is or other gaussian parameters :-/ I tried putting a 20x beam expander in front of it without any apparent changes; this LD bugs me out because I never had issues with other LD or SM fibers. If you find something, please report your obse...
by Luc
Tue Jun 25, 2024 4:35 pm
Forum: OpenRAMAN
Topic: Calibration Image Issue
Replies: 11
Views: 782

Re: Calibration Image Issue

No you'll need something like https://www.thorlabs.de/thorproduct.cfm ... ber=M29L02 with a 19mm achromat lens for collimation
by Luc
Mon Jun 24, 2024 7:35 pm
Forum: OpenRAMAN
Topic: Calibration Image Issue
Replies: 11
Views: 782

Re: Calibration Image Issue

Hi, It's always a multimode fiber (I don't own single mode ones). Just I don't have one with a large core so I compensate with a XY stage but it's an inferior solution. It's really a question of getting light on the slit and not 100um next to it. Don't forget to rotate the grating, it's possible tha...
by Luc
Mon Jun 24, 2024 3:35 pm
Forum: OpenRAMAN
Topic: Calibration Image Issue
Replies: 11
Views: 782

Re: Calibration Image Issue

OK I think I narrowed it down :)

What wavelength is your fiber locator?

I presume you're simply imaging the slit out of the camera active area. Try rotating the grating when the slit is vertical. You should find the signal then.
by Luc
Mon Jun 24, 2024 1:23 pm
Forum: OpenRAMAN
Topic: Calibration Image Issue
Replies: 11
Views: 782

Re: Calibration Image Issue

Yes indeed, but then I don't understand why you don't see the slit in the vertical position :-/ Nonetheless, you can't align with just one ray (laser) and need at the very least two -- the more the better, provided you can cleanly discriminate them. Hence the neon lamp. Other lamps could work but ba...
by Luc
Mon Jun 24, 2024 7:00 am
Forum: OpenRAMAN
Topic: Calibration Image Issue
Replies: 11
Views: 782

Re: Calibration Image Issue

Yes, the neon light bulbs like these work great. You will have to solder a ~300kohm resistor to it and plug it to the main (110V/230V) -- take care not to hurt yourself. What I'm surprised is the width of the light and the fact that you don't see it as you rotate the slit. Do you use a collimator wi...
by Luc
Sun Jun 23, 2024 9:18 pm
Forum: OpenRAMAN
Topic: Calibration Image Issue
Replies: 11
Views: 782

Re: Calibration Image Issue

Quick question... is your slit horizontal instead of vertical by any chance? That would explain why it's so broad