Abstract

Recently multimode lasers have been intensively studied for their antiphase dynamics (AD) [1-2]. The simplest manifestation of AD is as follows. If the laser is oscillating with N modes, the dynamics of each mode is characterized by N relaxation oscillation frequencies while the total intensity, which is simply the sum of all modal intensities, displays in its dynamics one relaxation oscillation frequency only. This frequency is the single mode relaxation oscillation frequency Ω_R that is also the largest of the N frequencies. This properly has been reported experimentally in the transient relaxation of multimode lasers in a Fabry-Pérot configuration, in the response of such lasers to an external periodic modulation and in the noise spectrum of multimode lasers [2,3]. The analytic study of these lasers is based on the Tang, Statz and deMars (TSD) rate equations [4]. Analytical and numerical studies of the TSD equations show that two key factors for the appearance of AD are the large value of k (the ratio of population to photon lifetimes) and small differences in modal gains. The purpose of this paper is to present new results on the linear stability analysis of the TSD equations and investigate the disappearance of low relaxation frequencies.

© 1996 IEEE