Fiber‐optic acoustic transducer utilizing a dual‐core collimator combined with a reflective micromirror

Abstract

AbstractA photonic acoustic transducer utilizing a dual‐core fiber collimator and a membrane type micromirror was proposed and demonstrated. The collimator and the mirror serve as a compact optical head and a reflective diaphragm, respectively. The micromirror diaphragm is suspended by a silicon bar connected to a frame, allowing for displacement induced by acoustic waves. The optical head incorporating dual collimators integrated in a single housing provides light to and receives it from the diaphragm. It facilitates the initial adjustment of the distance between it and the diaphragm, thanks to its slowly varying beam profiles. For the proposed acoustic transducer, the static characteristics were measured to find the operation point defined as the optimum distance between the head and the diaphragm, and a frequency response with a variation of ∼±5 dB was achieved for the range of up to 3 kHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1833–1836, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21789