The optical noise of low-coherence sources coupled to optical networks can make a significant contribution to the overall output noise in certain applications. The characteristics of this noise depend on both the statistical properties of the source and the architecture of the network. The case of constant-amplitude and random-phase sources has already been studied in considerable detail. The present study deals with the case of a source obeying Gaussian statistics coupled to a linear, single-mode optical network. Utilization of the well-known properties of Gaussian random processes allows us to derive a general expression for the spectral density of the output optical noise. For the special case of systems that have a periodic frequency response and are polarization degenerate, a factorization between the source and the system parameters is achieved, and an explicit expression for the system-dependent factor is derived. The intensity of the noise considered in this study increases with the source power, becoming comparable with the shot noise at source powers of a few microwatts. The general theory is applied to the special case of the fiber-optic Fabry—Perot resonator.
© 1990 Optical Society of America
Yitzhak Weissman, "Analysis of optical radio-frequency noise produced by a linearly filtered Gaussian source," J. Opt. Soc. Am. B 7, 127-133 (1990)