Log on June 19, 2020

What I did

I installed the servo which was from TAMA and modified.
Then I tried to lock by adjusting the gain and the offset.

Result

I could lock the laser to the cavity though the lock lasted only 10 sec or so.
The transmitted beam power was about 160 uW.
As the transmittance of the mirror is 0.017%, the intra-cavity power is estimated as about 1 W which is a reasonable value.

Next step

I am planning to lock the laser under the vacuum pressure to check whether I can or not lock when the turbo pump is on.
Also I will measure the open loop TF to see the phase margin and so on.