Homemade spectrum analyzer

[photonic]

Has anyone seen plans for a homebrewed way to determine the frequency of a specific (laser) light output?

 

[NewBie]

If you use a prism or better yet, a diffraction grating, you can cast a spectrum on a surface. There are numberous known light source spectral lines that you can then use to mark off the wavelength on a plate. From there, you just make a scale. Instant wavelength sensor.

 

[photonic]

What about for the infra-red parts of the spectrum? I guess if the scale is linear you can extend it but I would think that the prisim method wouldn't be all that accurate. Have you tried it?
Thanks,
Photonic

 

[NewBie]

For IR, you can use IR sensor and slide it on the scale, find the peak, or you can use a thermistor painted black and read the temperature.