This week was a research phase. I'm putting together parts for a spectrometer.

Ingredients:

• The Optics of Spectroscopy - A TUTORIAL By J.M. Lerner and A. Thevenon
• Inexpensive 102-element photodiode array with built-in ADC
• Inexpensive holographic diffraction grating film

I just need some mirrors and I'm mostly set. I'm going with what is mostly a Czerny-Turner monochromator design, with two differences. First, the grating is a transmission grating, not a reflection grating, so the bottom half "flips around". Second, I'm using an imaging sensor rather than a single exit slit, so it's not actually a monochromator.

And here's a bonus photo I took of some lightbulbs through a diffraction grating. Incandescent on top, CFL on the bottom: