2005/02/28 by B. Sheard, B.S. Sheard, M.B. Gray +7 · 1 citation
Chemistry · Engineering · Physics and Astronomy · #Acoustics #Detector #Laser #Loop (graph theory) #Mechanical and Optical Resonators #Noise (video) #Noise floor #Noise measurement #Noise reduction #Optics #Photodetector #Physics #Quantum #Quantum limit #Quantum mechanics #Quantum noise #Semiconductor Lasers and Optical Devices #Shot noise #Spectroscopy and Laser Applications
paper · doi:10.1109/jqe.2004.841611
openalex publication_date 2005/02/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/02
Experimental results for intracavity-laser intensity-noise suppression, or "squashing," manifested as reduced fluctuations on the transmitted field photodetector voltage are presented. It is experimentally demonstrated that a rigid optical cavity within the feedback loop is compatible with squashing. The observed closed loop detector noise floor is approximately 16 nV/sub rms///spl radic/Hz in the acoustic frequency range (/spl sim/100 Hz), well below the quantum limit due to shot noise of 148 nV/sub rms///spl radic/Hz. This corresponds to 19 dB of observed noise suppression below the quantum limit and is consistent with the measured disturbance suppression function of the feedback loop. We also present measurements demonstrating the orthogonality of the squashing and frequency-locking control loops.