Thanks for the link! I’ve been trying to figure out how to buy/make a Raman spectrometer for cheap (currently in a third world country too!). Have you built one yet? I’m having trouble finding the lenses needed (mostly because of my lack of knowledge). Any chance you know what to use?
I haven't found the lenses yet although supposedly https://www.thorlabs.com/ has them and someone else recommended these guys to me for finding more high quality diffraction gratings than the 'rave goggles' quality you can find on amazon https://www.edmundoptics.com/
Laser ($40): https://a.co/d/0wjNGBz
Diffraction grating ($12): https://a.co/d/6bpO8xm
Laser focusing lens: Not found
Fluorescence collection lens: Not found
Focusing lens: Not found
Collimating lenses: Not found