1 July 2015 Sagnac interferometer based stable phase demodulation system for diaphragm based acoustic sensor
Author Affiliations +
Proceedings Volume 9655, Fifth Asia-Pacific Optical Sensors Conference; 96550D (2015) https://doi.org/10.1117/12.2184271
Event: Fifth Asia Pacific Optical Sensors Conference, 2015, Jeju, Korea, Republic of
Abstract
A modified fiber-optic Sagnac interferometer with a stable π/2 phase bias is demonstrated for the demodulation of diaphragm-based acoustic sensors. The phase bias is obtained by introducing a nonreciprocal frequency shift between the counter-propagating waves. The system is passive and without complicated servo-control for phase stabilization. Interrogated by the proposed demodulation system, a 100 nm-thick graphite diaphragm-based acoustic sensor demonstrated a minimum detectable pressure level of ~ 450 μPa/Hz1/2 at the frequency of 5 kHz and the output signal stability is less than 0.35 dB over an 8-hour period.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jun Ma, Jun Ma, Yongqin Yu, Yongqin Yu, Wei Jin, Wei Jin, } "Sagnac interferometer based stable phase demodulation system for diaphragm based acoustic sensor", Proc. SPIE 9655, Fifth Asia-Pacific Optical Sensors Conference, 96550D (1 July 2015); doi: 10.1117/12.2184271; https://doi.org/10.1117/12.2184271
PROCEEDINGS
4 PAGES


SHARE
RELATED CONTENT


Back to Top