On Jan 17, 1:51*pm, Anders Wallin wrote:
Are both lasers on an optical table but with the spectrum analyzer on
a separate shelf or cart vibration isolated from the lasers?

Yes and yes!
I am starting to think the frequency jumping I am seeing might be because of current ripple in the PSU.
Looking at Sam's laser FAQ there are at least two options. Either the ripple reducer over hehttp://repairfaq.ece.drexel.edu/sam/smhpsrr1.gif

Hmm I was going to ask if anyone has used a capacitor multiplier at
high voltage.
http://en.wikipedia.org/wiki/Capacitance_multiplier
I have no idea if it can survive the turn-on transient of a HeNe.
Or if it would have to be 'bypassed' during the turn on stage.


or perhaps just more filtering capacitors on the output like many of the circtuits he (many 450V caps in series, with resistors in parallel over each cap)http://repairfaq.ece.drexel.edu/sam/laserhsc.htm

would a typical "brick" type HeNe PSU work with something like this on the output?:https://www.dropbox.com/s/epbwgox0tm...hv_filter2.png

The resistors in parallel with the caps aren't doing any low pass
filtering.
I think they are there to help balance the charge on the caps. (HV is
not my forte.) R2 and R19 with the caps do form low pass filters.

Sometimes if you can't figure out how to make something better, and
you're not sure what's causing the problem. You can learn something
by trying to make it worse.

George H.

Anders