A Novel Method to Extract Sound Information in Light and Achievement of High Performance and Advanced Functions in Optical Wave Microphone

我们进行了研究，以开发光波麦克风，它可以直接通过激光束检测声音，没有任何隔膜。本研究报告表明：（1）从音频波到低频超声波的所有声音频率都可以被检测到;（2）采用同轴多次反射系统或光学谐振系统可以大大提高灵敏度;以及（3）利用光纤可以实现不同入射角声音的分离测量和接收指向性的手控，束以检测空间分布的信号光（或由声音衍射的光）。

We carried out studies to develop the optical wave microphone, which can directly detect sounds by a laser beam without any diaphragm. In the present research report, it is shown that (1) all sound frequencies from audio wave to low-frequency ultrasonic wave can be detected, (2) the sensitivity can be greatly improved by using a co-axial multi-reflection system or an optical resonance system, and (3) the separating measurement of sounds with different incidence angle and the hand control of receiving directivity can be realized by using an optical fiber bundle to detect the spatially-distributed signal light (or the diffracted light by sounds).