Tsunami - Beckman Institute Laser Resource Center

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Maintenance
CAUTION
Do not use lens tissue designated for cleaning eye glasses. Such tissue
contains silicones. These molecules bind themselves to the optic
coatings and can cause permanent damage. Also, do not use cotton
swabs, e.g., Q-Tips" . Solvents dissolve the glue used to fasten the
cotton to the stick, resulting in contaminated coatings. Only use
photographic lens tissue to clean optical components.
General Procedures for Cleaning Optics
With the exception of the rod, the AOM, the GTI (ps configuration), and
prisms (fs configuration), all optics must be removed from their mounts
for cleaning. However, only mirrors MS, the output coupler Mlo, the
Brewster windows, and the beam splitter must be removed from their
holder to clean the second surface.
CAUTION
DO NOT remove or adjust fs prisms Prl to Pr4, or adjust the mirror
mounts of M6, M7, M8, or Ms. These optics are prealigned at the factory
and are not to be disturbed unless specifically told to do so elsewhere
in this manual. A service call might be required if disturbed.
WARNING
When replacing optics holders, DO NOT tighten them too much or
you will press the optic against the three steel alignment balls too hard
and chip the optic. Simply screw on the holder until you feel contact.
Also, be careful not to cross-thread the holder when you screw it on.
1. Use a squeeze bulb or dry nitrogen to clean away any dust or grit before
cleaning optics with solvent. If canned air is used, hold the can in
an upright position to avoid liquid freon from contaminating the optic.
2. Whenever possible, clean the optic using the "drop and drag" method
(Figure 9-1).
a. Hold the optic horizontal with its coated surface up. Place a sheet
of lens tissue over it, and squeeze a drop or two of acetone or
methanol onto it.
b. Slowly draw the tissue across the surface to remove dissolved
contaminants and to dry the surface.
Pull the tissue slow enough so the solvent evaporation front
immediately follows the tissue.