Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

Hello:

If you choose a waveplate or a rotator, ask the manufacturer about wavelength
range and power threshold.  In either case, the travel path through the optic
is a lot less than a Faraday Isolator.  The double Fresnel-Rhomb is ONE KIND of
rotator with 'broad' wavelength range, but the travel through the optical
material is big.  Make sure you don't have a front reflection from the optic (I
do not know if they can AR coat these optics).

I any case, if your laser is tunable... this may be a bigger obstacle.  You do
not want to realign for each wavelength.  I would chase down the main source of
reflection first.  Anyone else had to solve this problem?  My beam path is so
big, it is not a problem.

CVI tends to give good advice on their optics and knows about short pulsed
lasers.  No financial interest.  I do not know if the merge/purchase of Melles
Griot changes things.  Plenty of suppliers for these types of parts though and
any of them should be helpful.

Good luck!
Sophie
____________________________________________________
Sophie M. K. Brunet, Ph. D.
Research Officer
Optical Spectroscopy, Laser Systems and Applications
Chemistry 112 sessional lecturer
[log in to unmask]
306-966-1719 (office)   306-966-1702 (fax)
____________________________________________________
Saskatchewan Structural Sciences Centre
University of Saskatchewan
Thorvaldson Bldg.
110 Science Place
Saskatoon, Sk   S7N 5C9
____________________________________________________


Quoting Ann Haberman <[log in to unmask]>:

> Search the CONFOCAL archive at
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
>
> Dear List,
>
> Thank you all for the many helpful suggestions.
>
> One of the manufacturers of a Faraday isolator feels that a rotator
> by itself would be insufficient to reduce the reflected laser and
> indicated that a isolator would be necessary. Given the amount of
> dispersion I would get with just a rotator, I'm loathe to get an
> isolator. Their assumption is that the polarization of the reflected
> laser will be identical to the laser output. Is likely that it would
> be different ?
>
> The suggestion of using a 1/2 or 1/4 waveplate sounds like a good
> idea. Would there be less dispersion in this arrangement? What would
> be disadvantages of this compared to the rotator?
>
> Many thanks again for this helpful advice,
> Ann
>
> --
>
> Ann Haberman, PhD
> Department of Laboratory Medicine
> Yale University School of Medicine
> 1 Gilbert  St.
> TAC S541
> New Haven, CT 06510
>
> 203-785-7349
> 203-785-5415 (fax)
> [log in to unmask]
>