General preparations for the measurement
- Remove the large metallic knob for adjusting the SHG-crystal by pulling it up (it is just an allen key with a big knob).
- Remove the SAGA lid
- Make sure to identify where the oscillator and the amplifier is located, and where the beam leaves the SAGA.
- Make sure to update the SAGA performance log here: https://docs.google.com/spreadsheets/d/1lI-ZxHMRXOFWAu1hkjczYvH_5MR1QX7ztTX-jO8pw-c/edit#gid=0
Figure 1: Image of SAGA amplifier heads with lids on. The position of the SHG crystal knob and the lid screws are highlighted.
Figure 2: Image of SAGA amplifier heads with lid off. The oscillator and amplifier head are marked, as well as 2 potential positions for measuring the amplifier energy and 1 position for the oscillator energy output. Note that SAGA #1 is flipped compared to SAGA #2.
Oscillator measurement
- Place the energy meter head at the position marked in Figure 2
- Make sure the power meter is angled.
- Turn on the laser
- Open the shutter
- Wait for power measurement to stabilize
- Turn off the laser
- Remove the power meter head
Figure 3 shows the power meter head place at an angle during the measurement in SAGA #2. The placement of the power head in SAGA #1 is shown in Figure 4.
Figure 3: Power meter head measuring the energy from the SAGA #2 oscillator
Figure 4: Power meter head measuring the energy from SAGA #1 oscillator
Amplifier measurement
WARNING: A direct back reflection (even from the power meter diffuser) will burn the optics in the SAGA. Be very careful and make sure you are using a large angle for the power meter when doing the measurement.
- Place the energy meter head at the position marked in Figure 2
- Make sure the power meter has a large angle.
- Turn on the laser
- Open the shutter
- Wait for power measurement to stabilize
- Turn off the laser
- Remove the power meter head
Figure 5 shows the power meter head place at an angle during the measurement in SAGA #1. The placement of the power head in SAGA #2 is shown in Figure 6.
Figure 5. Power meter head measuring the energy from SAGA #1 amplifier. The power meter head is placed between the telescope and the SHG crystal.
Figure 6. Power meter head measuring the energy from SAGA #2 amplifier. The power meter head is placed within the final telescope.