Towards realizing opto-mechanical phase sensitive amplification*

Squeezed vacuum injection in gravitational wave detectors to reduce the impact of quantum noise can be complemented by phase-sensitive pre-amplification at the output. Losses in the readout chain, namely optical losses, cause decoherence allowing noise (including quantum fluctuations) to couple back into the system. This can be prevented by applying phase-sensitive amplification to amplify the signal quadrature beyond the limitations posed by phase-insensitive amplification, i.e., the standard quantum limit. 

This work describes a tabletop setup built to demonstrate such phase-sensitive amplification realized with an opto-mechanical nonlinearity, achieved with a gram-scale mirror on a cantilever, in a triangular optical traveling wave cavity with no detuning. In particular, it deals with the specific challenges of noise budgeting and the use of other experimental techniques for a macroscopic quantum-limited tabletop experiment in the audio frequency band.