Reports until 17:23, Tuesday 03 October 2023
GQuEST General
Daniel Grass - posted 17:23, Tuesday 03 October 2023 (11310)
Attenuating the laser with a mirror as a function of angle of incidence

Torrey and Daniel 10/3/2023

We measured the laser power coming out of the seeder to see if a Newport 10D20DM.8 could serve as a filter to image the light coming out of the amplifier. We measured the power incident, transmitted, and reflected for a few angles of incidence.

Data:

~<5 degree AOI:

Incident: 26.1 mW

Transmitted: 4.25 uW (0.00016 of the incident power is transmitted)

Reflected: 26.04 mW (0.9977 of the incident power is reflected)

Implied Absorption: 0.06 mW (0.0023 of the power is absorbed)

 

45 degree AOI:

Incident: 26.06 mW

Transmitted: 10.99 uW (0.00042 of the incident power is transmitted)

Reflected: 26.09 mW (more power is seemingly reflected than incident; some small measurment error)

Implied Absorption: 0 mW (none of the power is absorbed)

 

The conclusion is that the mirror's OD is between 3.4 and 3.8 depending on the AOI. This should work very well with a amplifier of 5 W, giving around 2 mW of transmission with little absorption and an easy to block reflected beam.

One complication is the back of the Newport 10D20DM.8 is frosted, potentially making the beam hard to profile.