Experimental demonstration of in-loop intracavity intensity-noise suppression

Author

Sheard, B.S. ; Gray, M.B. ; Slagmolen, B.J.J. ; Chow, J.H. ; McClelland, D.E.

Author_Institution

Dept. of Phys., Australian Nat. Univ., Canberra, ACT, Australia

Volume

41

Issue

3

fYear

2005

fDate

3/1/2005 12:00:00 AM

Firstpage

434

Lastpage

440

Abstract

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_rms/√Hz in the acoustic frequency range (∼100 Hz), well below the quantum limit due to shot noise of 148 nV_rms/√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.

Keywords

laser cavity resonators; laser noise; optical feedback; photodetectors; shot noise; disturbance suppression function; frequency-locking control loops; in-loop intracavity intensity-noise suppression; photodetector voltage; shot noise; squashing; Acoustic noise; Acoustic signal detection; Detectors; Feedback loop; Fluctuations; Gunshot detection systems; Optical feedback; Optical noise; Photodetectors; Voltage; Laser intensity-noise control; nonclassical light; quantum noise suppression;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/JQE.2004.841611

Filename

1397890