Spectral filtering

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thycore
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Spectral filtering

Post by thycore » Sun Dec 22, 2019 11:47 am

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

https://www.thorlabs.com/thorproduct.cf ... L05632.8-1

BobH
Posts: 403
Joined: Tue Jan 06, 2015 10:26 pm
Location: Mesa, AZ

Re: Spectral filtering

Post by BobH » Tue Dec 24, 2019 9:55 am

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: 760
Joined: Wed Jan 07, 2015 8:01 am

Re: Spectral filtering

Post by holomaker » Wed Dec 25, 2019 1:24 pm

Band pass and/or notch filter

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