Dear List,

I have a 1 year-old Spectra Physics Millenia Vs Diode-pumped laser on a
two-photon setup. It has had about 220 hours of use. Initially when it is
started, it will power up to over 5.5 W at 100% current. However, after
about 30 minutes the power at 100% current starts to drop. By three hours
it is down to about 4.5 W.  The temperature in the room is pretty well
controlled- it varied by less than 2 deg C over the three hours. In
addition, the bath temperature of the cooler stays very constant
throughout. Does anyone have an idea what might be going on? A collegue of
mine suggested that there may be a problem with the doubling crystal. The
technician at Spectra-Physics wants to simply increase the amount of
current going to the diodes to increase the power, but I am worried that
this might shorten their lifetime, and not solve the underlying problem.
Any suggestions?
******************************************************************

Don B. Arnold, Ph.D.
Assistant Professor
University of Southern California
835 West 37th Street
SHS 172, MC 1340
Los Angeles, CA 90089-1340
phone: (213)821-1266
fax: (213)821-1818
http://www.usc.edu/dept/nbio/ngp/Faculty/arnold-db.html