Today I locked the laser to the fixed folded cavity.
After the alignment work, I measured the output power by the power meter.
The output power was 4.7 uW.
This may be due to the alignment problem.
Using this value, one can estimate the intra-cavity power.
Since the transmittance of the mirror is 0.017 %, the intra-cavity power can be estimated about 28 mW.
There is room for improvement.
I am planing to improve the alignment of the mirrors and try to increase the output power to 100 uW.
Then I will try to lock with pumps on.
Also, some pedestals are to be replaced to vacuum copatible ones.