Re: Enterprise laser experiences

From: David L Haviland (David.L.Haviland@uth.tmc.edu)
Date: Fri May 18 2001 - 14:10:01 EST


Larry Arnold wrote:

> I would like to request info from people who use/know the Enterprise laser
> from Coherent.  I have always been uneasy with using this laser for
> simultaneous 488 and UV primarily because the laser is light regulated on
> only one of the lines at a time.  Thus, I worried that over time the
> unregulated line might change and affect experimental results.  Also for
> the unregulated line you just get whatever you want based on what power
> output you want from the regulated line (is this correct?).  Short of using
> filters to reduce the power if needed I assume this is the
> situation.  However, I have no direct experience and am now considering a
> system with that laser.  What has the experience been?  Is this a real
> worry but not actually realized?  What is the lifetime ratio of the 488/UV
> lines?  I appreciate your advice and thanks in advance.

Larry:

I have on on our Institute's Vantage and so far have been very happy with it.
Some of your questions I am unable to answer as I've yet to have the misfortune
of replacing it.   On the Vantage, the optics are set so that the UV is
redirected in an manner independent of the 488, so that both hit the stream
separate from each other with the 488 being first.  The UV, and HeNe, are
secondary lasers in this system.   I have to use the 488 primary as the means
of triggering and tell the machine to look for a signal in the secondary.    If
I don't, all is ignored.   This is a long winded way of saying that with time,
yes, the UV power has gone up when set for regulation of the 488, but unless
I'm looking for something off the UV as well, it doesn't make any difference
what effect the UV has on what I see with the 488.

I would say it isn't a worry for me.  I once had a user that wanted to use
Hoercst (?) and PI at the same time so we opted to regulate the UV.  The 488
didn't drift much to make any real difference, maybe plus/minus a couple of
miliwatts if that.   That was also a long time ago...

I can't speak to the lifetime issues either as they both come from the same
source, I figure if I lose the 488, I'll lose the UV too.

Hope this helps,
David
==========
David L. Haviland, Ph.D., Asst. Prof. Immunology
University of Texas - Houston, H.S.C.
Institute of Molecular Medicine, R907
2121 W. Holcombe Blvd.,  Houston, TX  77030
713.500.2413-Voice//713.500.2424-FAX
-----------------
Thot for the Day:
Things could be worse...  Martha Stewart could be your mother-in-law.
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