Kiwamu and Steve,
This is one of the better oplev set up we have. Single bounce from TM, no mirror on stack. One lens and one mirror on ISCT. Old Uniphase 1103P laser on heafty 3" od mounts.
Somewhat big ~5-6 mm spot on qpd in 1,300 counts.
The intensity noise effect can be seen at 1 Hz and 3-20 Hz
Oplev servo was OFF