Marcia Woda asked about experiences using dye lasers pumping
rhodamine 6G. Our (good) experience with this beast is outlined
below.
We have been using a Coherent 599 dye laser pumping rhodamine 6G
since 1986. We use the laser from 8 to 12 hours per day, 5 days
a week and change the dye once per year. In order to maintain
a power output of 400mW, cleaning and realignment of the optics
is necessary every 1 to 2 months. The dye seems to be very
sensitive to temperature changes and therefore the power output
usually drifts for at least an hour after cold startup. Except
for some tweaking by Coherent when the laser was new, I have
serviced the laser since it was installed, including dye changes.
The learning curve for servicing this beast took several years
and included some trial and error along with calls to Coherent.
Because it can be tuned to a wavelength that falls between the
upper end of PE emission and will still directly excite Texas Red,
Cy5, and APC, I think this laser is optimal for doing multi-color
(e.g.; 3 to 4 color) experiments. In our hands, it has been
a real workhorse. I know that other labs have disliked their
dye lasers because of the maintanence headaches and there are
at least several of these things laying around unused. It does
require constant tweaking to maintain the desired power output.
One other drawback is that it requires a big, powerful, water
cooled pump laser which makes it more expensive to operate.
As a core research lab, we find it an essential part of our
instrumentation.
Justin Fishbaugh
University of Iowa
Flow Cytometry Facility