B-70315EN/02 8.LASER OPTICAL SYSTEM
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8.4 OBTAINING A MAXIMUM POWER
8.4.1 Preparation
(1) Using the conditions Pc = rated output, Duty cycle = 15%, and
Frequency = 100 Hz, adjust the duty cycle to determine the
actual conditions for internal discharge.
If a large output is used, the mode present when a maximum
power is obtained is not always the best due to thermal distortion
of each mirror. A capability of detecting an output variation due
to base output fluctuation, tester resolution, chiller temperature,
and so forth is required. If the discharge area is narrow, the
output variation dependent on a shift of the internal optical axis
becomes small.
(2) Connect the tester to the BNC terminal CN59 of intermediate
PCB B.
(3) Start internal discharge. Start adjustment when the output
becomes stable after 5 minutes.
Fig.8.4.1 External view of intermediate PCB B
8.4.2 Procedure
By using two mirrors A and B with mirror A used as the reference,
find a position where a maximum power is obtained based on mirror B.
While turning mirror A in one direction in steps of an interval of the
micrometer, for example, 1 division (10 µm) or 2 divisions (20 µm),
adjust mirror B for each division, and obtain a maximum power at
each point of mirror A. Graph the data at each point of A, and
determine a mirror A position representing a maximum power. Then,
by aligning mirror A at such a position, adjust mirror B to obtain a
maximum power. Two micrometers are provided for each mirror. So,
be sure to obtain a maximum power with one axis, then obtain a
maximum power with the other axis. Do not move the X-axis and
Y-axis at the same time.
Output terminal
in alignment procedure