Digital Output Noise-Cancelling Fiber Optic Microphone

The work proposed will develop a Noise-Canceling Fiber Optic Microphone (NCFOM) with a digital output signal for use with AF communication systems. A first-order vented cavity NCFOM design and a dual diaphragm NCFOM design will be analyzed using already developed equivalent frequency circuits to determine the parameter values necessary for maximum directivity. Venting of the acoustic cavity or a passive diaphragm in the acoustic cavity will be used to adjust the directivity and noise cancellation characteristics of the microphones. A commercially available integrated circuit that converts light intensity to frequency will be used to provide a digital output signal for use with communication systems. This work would produce a microphone that could be used in both electrical and acoustic noisy environments.