Feasibility of guided-wave optical microphone based on elasto-optic effect

Hiroyuki Nikkuni; Masashi Ohkawa; Seishi Sekine; Takashi Sato

doi:10.1117/12.649176

6 December 2005 Feasibility of guided-wave optical microphone based on elasto-optic effect

Hiroyuki Nikkuni, Masashi Ohkawa, Seishi Sekine, Takashi Sato

Proceedings Volume 6049, Optomechatronic Sensors and Instrumentation; 604907 (2005) https://doi.org/10.1117/12.649176
Event: Optomechatronic Technologies 2005, 2005, Sapporo, Japan

Abstract

In this paper, the feasibility of a glass-based guided-wave optical microphone is described. The optical microphone consists of a rectangular diaphragm and a straight waveguide on the diaphragm. The sensitivity of the microphone and the resonance frequency of the diaphragm are dependent on the diaphragm dimensions. In this study, to confirm operation of the proposed optical microphone, the target values for phase sensitivity and resonance frequency were set at 1.3 mrad/Pa and 5 kHz, respectively. By design considerations, the diaphragm dimensions were determined to be 16 mm × 16 mm × 0.15 mm. After fabrication, a sound wave of 1 kHz and 25 Pa, corresponding to 122 dB-SPL (sound pressure level), was applied to the microphone. In the experiment, the intensity-modulated output with the same frequency as the applied sound wave was obtained, but the observed output was unexpectedly caused by misalignment of the optical components due to mechanical vibration. The estimated output signal by the normal operation of the microphone for a sound pressure of 25 Pa was 1/10 - 1/100 of the noise level, according to the measured output characteristic to static pressure. In order to detect normal speech ranging from 55 to 65 dB-SPL, the S/N ratio should be improved by a factor of more than 10⁴.

Citation Download Citation

Hiroyuki Nikkuni, Masashi Ohkawa, Seishi Sekine, and Takashi Sato "Feasibility of guided-wave optical microphone based on elasto-optic effect", Proc. SPIE 6049, Optomechatronic Sensors and Instrumentation, 604907 (6 December 2005); https://doi.org/10.1117/12.649176

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available