| 摘要 |
PURPOSE:To obtain a microphone of low distortion, a broad band and a broad dynamic range by excluding a diaphragm receiving an acoustic wave. CONSTITUTION:The acoustic wave S is inputted into an acoustic input part 1 which is released and has air in it. A laser beam B moves back and forth between a pair of reflecting mirrors 3 and 4 to be one component of a Fabry- Perrot saler beam interferometer so as to cross the acoustic wave S. The optical path length of the laser beam is optically and equivalently changed with the change of the roughness/fineness of air corresponding to the accoustic pressure of the accoustic wave S at each time, and a light receiving device 5 catches it. |
