title: All-optical low noise fiber Bragg grating microphone.
abstract: We present an all-fiber design for a microphone using a fiber Bragg grating Fabry-Perot resonator attached to a diaphragm transducer. We analytically model and verify the fiber-diaphragm mechanical interaction, using the Hänsch-Couillaud readout technique to provide necessary sensitivity. We achieved a noise-equivalent strain sensitivity of 7.1×10-12ϵ/Hz, which corresponds to a sound pressure of 74  μPa/Hz at 1 kHz limited by laser frequency noise and yielding a signal-to-noise ratio of 47±2  dB with a 1 Pa drive at 1 kHz, in close agreement with modeled results.
authors.forename: Chathura P
authors.initials: CP
authors.lastname: Bandutunga
authors.forename: Roland
authors.initials: R
authors.lastname: Fleddermann
authors.forename: Malcolm B
authors.initials: MB
authors.lastname: Gray
authors.forename: John D
authors.initials: JD
authors.lastname: Close
authors.forename: Jong H
authors.initials: JH
authors.lastname: Chow