Fabry-Perot question

From: Níkola Heímpel (niki0904_at_nurfuerspam.de)
Date: 12/01/04 

Date: Wed, 01 Dec 2004 14:33:15 +0100

If I have a spherical mirror Fabry Perot interferometer and do get some
signals, but they are way too small, what reason could that have?

We do see signals, FSR as expected, fairly easy. They are already quite
narrow (Finesse around 20) and we see two modes of our HeNe Laser. Just
the transmitted intensity is very small, only about 1/1000 of the
initial intensity, and I don't understand why.

What would be the most likely reason:

- insufficient mirror surface quality, destroying the wavefront after
some cycles?
- misalignment (hard to believe, since we have sensitive alignment
mechanics and tried for a very long time - also always get the same
values, even after taking everything apart and trying again, and the
maximum intensity we get is also very sensitive to adjustment changes)
- something completely different?

We use self-coated mirrors, so mirror quality could well be an issue.
But why are the peaks narrow then? I expected to get either small and
broad peaks, or huge and narrow ones. To me it looks like I'm "losing"
intensity somewhere.

Thanks for any help.
Nikola

Relevant Pages

  • Re: Fabry-Perot question
    ... > signals, but they are way too small, what reason could that have? ... > We do see signals, FSR as expected, fairly easy. ... > initial intensity, ... > We use self-coated mirrors, so mirror quality could well be an issue. ...
    (sci.optics)
  • Re: Einsteins lopsided caricature of space and time
    ... >>> The movenment of the mirror doesn't really matter. ... >>> flight times of the signal before and after the reflection ... > will take a time x'/, as measured in your frame. ... signals). ...
    (sci.physics.relativity)
  • Re: Q: Why do DSLRs need mirrors and prisms?
    ... reason that DSLRs still have mirror boxes and pentaprisms? ... If it did not have a pentaprism, it would not be a reflex camera, would ... The main reason for the DSLR is speed. ...
    (rec.photo.digital.slr-systems)
  • Re: Understanding SR - simultaneity
    ... For spacetime diagram see http://users.pandora.be/nicvroom/dirk1.htm ... When you synchronise the Left mirror, ... not see the signal and the front of the train together. ... He will See the reflected signals always simultaneous. ...
    (sci.physics.relativity)
  • Re: The need for a recumbent bike....
    ... bicycling, set on the side of my head so that I could see what's happening to the front, sides and to a much larger extent, the rear. ... ...Such mirrors don't work real well on upright bikes, because if you are positioned aggressively all the mirror shows you is your own shoulder. ... Anyone who tells you that turning your head to look or "listening for cars behind you" is just as effective as a good mirror is a simple fool. ... As for signaling rider intent, there are a couple companies making bicycle turn signals and overall I like the concept, but not the products offered. ...
    (rec.bicycles.tech)