Laser mode partition noise in lightwave systems using dispersive optical fiber

Abstract

Semiconductor laser mode partition noise (LMPN) can impair analog optical systems, but this phenomenon has not previously been well-characterized. Theoretical expressions for the noise spectra that result when light from a nearly single-mode or strongly multimode semiconductor laser is passed through a length of dispersive optical fiber are presented and have been tested experimentally. A widely used model is found to greatly overestimate the partition noise of a DFB laser; a model for the strongly multimode case is found to match experimental results for a multimode laser. It is observed that partition noise can be significant even for multimode lasers operating near the fiber dispersion minimum.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>