Figure 5-5. Example Of Laser Performance Dependence On The Operating Current - NORTHROP GRUMMAN Patara I User Manual

Figure 5-5. Example of Laser Performance Dependence on the Operating Current

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current to reach 99.5 percent of the peak power. This is the proper operating
current. In this example, the operating current would be 22.9 A.
The slight difference between the actual operating current and the test report value
may be due to the performance difference of the chillers. An increase in the
operating current can compensate for the aging of the Patara laser diodes.
6. Peak up the laser with adjustment of the cavity mirrors.
WARNING
. Making mirror adjustments can be non-reversible. Do this step only when all
the steps above have been completed and the laser does not meet the specifications
with the correct settings.
a. Locate the access holes for high-reflection mirror (HR) and harmonic
mirror (HM). Notice the positions of HR and HM mirrors with respect to
the direction of the laser output in Figure 5-6.
b. Remove screws from access holes only in a dust free environment.
c. Use a 1/8" ball driver to make adjustments. A fine adjustment is a 1 degree
or less rotation. A small adjustment is about a 2° rotation. A coarse
adjustment is 15° to 20° rotation. If coarse adjustments are needed to
obtain performance, reduce operating current by 2 A. Return to normal
operating current when making small and fine adjustments.
d. The screws for the adjustments of the vertical tilt angle and the horizontal
tilt angle are illustrated in Figure 5-6.
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Chapter Five: Maintenance
Patara I and II Laser User Manual