On fiber-optic hydrophone noise-equivalent pressure

Abstract

A recently published mathematical model of a fiber-optic hydrophone by Shajenko et al. [J. Acoust. Soc. Am. 64, 1286–1288 (1978); 66, 1557 (E) (1979)] implies that the limiting noise-equivalent pressure depends on the photodetector gain. Further analysis shows that the gain term in the equation for the noise is exactly cancelled out by another term also appearing in the equation. The model is rederived in this paper where it is shown that this dependence does not exist. The resulting expression for noise-equivalent pressure is consistent with the results presented in the latter of the references cited above.