[Sander, Torrey]
First operation of the amplifier with the pump current running. First, there seems to be some slight discrepancies between the manual (https://mccullerlab.com/logs/lab/index.php?callRep=11279) and actual operation. The manual instructs:
- Turn on seed light.
- Turn amplifier key, after 30 seconds the enable/disable button stops flashing and there is ~300mW of light.
- Adjust laser current, press enter, then click enable.
In reality it goes like:
- Turn on seed light.
- Turn amplifier key (the enable/disable button flashes indefinitely, says it is supposed to be 30 seconds).
- Press the enable button (Only now is there light, manual suggests there should be light before this).
- Use knob to highlight "current", press enter, change current with knob and press enter to apply amplification.
Only mention this because the manual explicity says, "To enable the power amplifier emission, press “Enable/Disable” on the front panel", which is not the case. On to the characterization.
We first calibrate how much power is being reflected by the BS to infer how much power is coming out of the amplifier. This is 1.45%. We then vary the amplifier pump current and measure the power reflected off the BS. Data in attached plot. It seems our maximum power out of the amplifier is just under 14W. Additional we look at the beam shape at each pump current. An example is attached as well as all of the profiles taken. Big take away here is the beam shape does not seem to vary with pump current.
Also as an aside we varied the input power to the amplifier, and as Lee suggested, the amplifier input saturates as any amount of input power did not change the output power (for input power >14 mW).
