ASA 125th Meeting Ottawa 1993 May

3aEA1. High-temperature fiber optic lever microphone incorporating a single fiber.

Frank W. Cuomo

Dept. of Phys., Univ. of Rhode Island, Kingston, RI 02881

Trung D. Nguyen

Old Dominion Univ., Norfolk, VA 23508

Allan J. Zuckerwar

NASA Langley Res. Ctr., Hampton, VA 23665

The fiber optic lever microphone [Hu et al., J. Acoust. Soc. Am. 91, 3049--3056 (1992)], as described previously, contains a central transmitting fiber surrounded by six receiving fibers placed with the distal end in the vicinity of the reflecting microphone membrane. Recently, a new approach consisting of a single optical fiber connected to an optical fiber coupler has been implemented. This design provides increased optical throughput, ease of fabrication, improved stability with temperature cycling, and more repeatable sensitivity. The two embodiments will be compared with regard to their theoretical optical transfer functions and experimental performance with temperature cycling to 1000 (degrees)F.