Continuum Surelite EX 10, Operation And Maintenance Manual

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Continuum Surelite Laser
54 996-0207
Figure 33 Cavity closed with no lasing
Q
UARTER
-
WAVE PLATE
The plate used introduces a quarter wave rotation to photons at 1,064 nm as they pass in
either direction through the plate. The plate has a clear aperture of 15 mm and is
mounted at a beam height of 43 mm.
T
IMED PULSE GENERATED BY
PCU
The control unit tracks the firing of the flashlamps in the laser head and then at a
preselected delay of ~200 µs triggers the Marx bank with a +15 V pulse. The signal is
normally set to fire at the peak of the gain curve of the oscillator YAG rod.
M
ARX BANK
(750V)
This board charges 7 capacitors in parallel and then discharges them through fast
switching transistors in series so that the voltage on each capacitor is summed. This
generates an ~-4 kV pulse with a rise time of 20 ns. This board is in a metal box next to
the Pockels cell.
750
VOLT POWER BOARD
This board, located above the oscillator cavity in a small box with the Marx bank,
generates the dc voltage necessary to power the Marx board. The dc voltage is
adjustable by a pot accessible through a hole in the top of the laser bench. Turning the
pot clockwise raises the voltage.
C
AVITY CLOSED
The beam propagating within the oscillator cavity makes a double pass through the
Pockels cell and
λ
/4 plate. At 0 volts on the Pockels cell (PC) it adds no rotation while
the
λ
/4 plate adds 45° with each pass, giving a total rotation of 90°. Thus the horizional
beam that transmitted through the plate polarizer is rotated to vertical and is rejected by
the polarizer and no oscillation occurs.