Optical domains in fiber lasers

Abstract

The formation mechanism of optical domains in multipulse fiber lasers was investigated. Optical domains consist of a square-shaped condensed phase of pulses derived from the slow evolution of gain. With the cross-gain saturation effect of wavelength-dependent or polarization-dependent condensed phases in the cavity, color domains (CDs) exist in dichroic fiber lasers, and polarization domains (PDs) in quasi-isotropic lasers. These operations can be described as a dynamic equilibrium, in which two signals compete and coexist in the cavity and have inverse duty cycles. In this paper, we investigate the analogies and the differences between CDs and PDs.