[ATM] laser and eye damage
richard at foucault.co.uk
Fri Sep 10 20:11:55 JST 2010
----- Original Message -----
From: "Anthony Stillman"
> The problem was the coherence length (bandwidth) and mode jumping.
Yes, it always is with solid state lasers which is why (in my and
others opinions) they are not suitable for interferometric work. Gas
lasers are better, and much better still if stabilised. I was lucky
enough to pick up a stabilised HeNe laser with a faulty PSU and
repaired it. It is switchable between frequency or amplitude
stabilisation. It is remarkably simple how they stabilise the tubes
using a small magnet and coil, the Zeeman effect, and a heater.
Coherence length is 100's of meters.
OOI, what method did you use to measure RI ?
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