How to measure a laser diode's Wavelength

Question

I have some laser diodes. I want to know how to measure the wavelength of laser diodes ranging from visible to near infrared? (300 nm to 1100 nm)

What type of instrument/meter do I need to use? spectrometer, spectrophotometer, wavelength meter, reflectometer, oscilloscope or what and how?

This question recently came up on physics.SE, and Floris's answer to the question is quite excellent. How to measure the wavelength of a laser pointer? — Chris Mueller, Jul 06 '15 at 11:51
What sort of resolution do you need? (a few nm?) I'm think a wave-meter will be over kill for you. (and too expensive) A spectrometer would be fine. Or as Chris M. links to above get a diffraction grating, measure the angle and do the math. — George Herold, Jul 09 '15 at 18:28

score 4 · Answer 1 · answered Jul 06 '15 at 01:28

4

You want a wavelength meter if you have one or otherwise a spectrometer. In more detail:

A wavelength meter uses an interferometer to measure wavelength. It can measure wavelengths very accurately.
A spectrometer measures a spectrum, that is intensity vs wavelength. The wavelength at the peak intensity is what you are looking for.
A spectrophotometer is used to measure the transmission spectrum of some material. This is not what you want.
A reflectometer measures reflectivity. Again, not what you want.
Oscilloscopes measure electrical voltage vs time. Again, not what you want.

answered Jul 06 '15 at 01:28

John1024

Thanks for help.Do you know any basic entry level Wavelength meter model # ?. – SARDAR TARIQ Jul 07 '15 at 15:06
Good sources for optical equipment like this are newport.com and thorlabs.com. If there is an inexpensive version, then edmundoptics.com will likely sell it. – John1024 Jul 07 '15 at 18:01

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