Abstract

Simultaneous measurement of underwater acoustic field and environmental temperature using a fiber Bragg grating (FBG) is carried out by utilizing an active feedback control of optical source wavelength. The operation principle of the sensor is based on the intensity-modulation scheme. The linearity and stability of the sensor is high in the measurement of both the acoustic field and temperature. The resolution of the temperature measurement is as high as 0.038 °C, which is, to the best of our knowledge, highest obtained without using the interferometric method. From the viewpoint of practical application, furthermore, time division multiplexed operation is demonstrated by constructing a FBG sensor array in which two FBG sensors are parallely arranged by using an optical switch.

© 2006 IEICE