Spectral filtering

Starting point for beginners questions.
User avatar
thycore
Posts: 77
Joined: Sun Jan 15, 2017 8:56 am
Contact:

Spectral filtering

Post by thycore »

Anyone experienced this kind of spectral filter to clean cheap Laser’s output ?

https://www.thorlabs.com/thorproduct.cf ... L05632.8-1
BobH
Posts: 440
Joined: Tue Jan 06, 2015 10:26 pm
Location: Mesa, AZ

Re: Spectral filtering

Post by BobH »

That is an interference filter, not a spatial filter. It's used with broadband light to narrow the wavelength range that is transmitted, and transmits a range that is centered on a laser wavelength.

A spatial filter uses a lens to focus laser light to a point that is centered on a pinhole made in a steel disk. Light that was scattered by things like dust particles on lenses or mirrors upstream gets focused to different, off-axis places by the lens in the spatial filter assembly. The pinhole only passes the main beam, not the scattered light, and thereby gives the resulting (now expanding) beam a smooth uniform appearance.
holomaker
Posts: 772
Joined: Wed Jan 07, 2015 8:01 am

Re: Spectral filtering

Post by holomaker »

Band pass and/or notch filter
Post Reply