PDH parks at the discriminator zero. Residual AM and etalon tilt the in-band conversion well off that zero. NSL dithers a slow bias on the same lock.
Peterson Quantum Sensing
Noise-Stationary Locking — a supervisory loop that parks the instrument where measurement-band noise is stationary. It does not replace PDH, squeezing, or a witness subtractor.
PDH parks at the discriminator zero. Residual AM and etalon tilt the in-band conversion well off that zero. NSL dithers a slow bias on the same lock.