Optical Fiber Coupler Array for Multi-point Sound Field Measurements

A pressure-sensitive device using an optical fiber coupler is proposed, and it is integrated to an array system to measure sound field distributions. The optical coupling between two optical fibers is modulated by the applied sound field with the use of a membrance mechanically connected to the coupler. In the array system, a large number of the optical coupler sensors are connected two-dimensionally, and sound pressure at every sensor can be measured by switching the input light sources in turns. The basic array system based on the principle is made for trial, and its performances are demonstrated.