Manuel, Eleonora

I checked the pump power vs laser current with the power meter PM100D with the head S145C ( Integrating Sphere Photodiode Power Sensor, InGaAs, 800 - 1700 nm, 3 W ).
It doesn't work with the chopper modulation, so I turned off the chopper. The angle of Input Power Controller (IPC) is set around the minimum of transmitted power because the power meter head has 3W of range.
Result: see the first plot.
Every time the current is changed, the laser needs some time (about 20 min) to stabilize. Since I changed the current without waiting for this time, the plot is noisy.

Then I set the laser current to 1.5A and rotated the angle of the IPC to change the power in a more stable way. I measured the power for different angles, without the chopper modulatoin, with two power meters: the PM100D-S145C and the Ophir-Vega (that has a larger range). Then we repeated the measurement with the chopper on and measured it with the Ophir-Vega to check if the ratio with and without chopper is 0.5.