Dynamic Range Extension for Heterodyne Fiber-Optic Hydrophone by Using Instantaneous Frequency-Tracking Method

Abstract

This letter proposes an instantaneous frequency tracking method to extend the dynamic range for heterodyne fiber optic hydrophones (FOHs). They are used directly to compensate for large signal amplitudes. The working principle is discussed, and simulations are conducted. The simulations achieve at least 20 dB dynamic range improvement.