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5. Plug the piezo element’s lead into the connector on the front of the Series 101 laser head labeled
"PZT".
6. Split the signal from the Q-switch trigger source and route this signal to the BNC connector on
the front of the Series 101 laser head labeled "TRIGGER IN".
2.2.2 Gross Mirror Alignment
All seeder/host laser systems require some beam steering mirrors to manipulate the seed beam
into the host cavity and make the host and seed beams colinear at the output of the host laser. By
centering the seeder output on the host laser output using the turning mirrors, and then fine tuning
the turning mirrors to minimize the Q-switch build-up time, the spatial overlap can be optimized. A
procedure for centering the seeder output on the host laser output is outlined below and assumes the
three mirror system shown in Figure 2-6. Optimization is discussed in Section 2.2.5.
1. Turn the host laser to low energy, long pulse operation.
2. Turn the Control Switch and Key Switch on the injection seeder to ON. The emission indicator
light should turn on. Confirm that there is output at the seeder with an IR card.
3. Using an IR card or viewer, determine if the seed beam exists at the output of the host laser. If it
does exist, proceed to Step 6.
4. If the seed beam does not exist at the output, check that the seed beam and host beam are
overlapped (colinear) between mirrors #1 and #2.
a. Turn on the host laser flashlamps and adjust the power such that the host laser is just above
threshold.
b. With the IR card just before mirror #2 and facing the seeder, check to see if the seed beam is
centered on the host beam. If not, use mirror #1 to steer the seed beam as required.
c. With the IR card just in front of mirror #1 and facing the host laser, check to see if the host
beam is centered on the seed beam. If not, use mirror #2 to steer the host beam as
required.
5. With the host laser off, the faint seed beam should now be observable at the output of the host
laser. If not, repeat step 4.
6. Using an IR card or viewer, alternately observe the seed beam and host laser beam. Adjust
mirrors #1 and #2 until the seed beam is centered on the output coupler. Make adjusts in
small increments so as not to completely loose the seed beam.
2.2.3 Q-switch Voltage Optimization
The Marx bank voltage is optimized by the following procedure.
CAUTION: Gross misadjustment of the Q-switch voltage can cause excessive power to be
returned to the seeder causing damage to the Faraday isolator and/or laser.
Such damage is excluded explicitly from Lightwave’s warranty. Return energy
must be kept <10 mJ/pulse.
1. Place a power meter between mirrors #2 and #3.
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