Modeling a diode pumped Er:Yb:glass laser with Co²⁺:spinel as a passive Q-switch

Abstract

In order to develop an efficient eye-safe laser, operating in the 1.53 µm region, we have written software that models the performance of a passively Q-switched Er:Yb:glass laser with a divalent cobalt Co 2+ :spinel saturable absorber. At present a 0D model, which uses a plane-wave approximation, has been completed. The model is based on a set coupled first order differential equations that describe the laser dynamics. These equations represent a two-level Yb 3+ diode pump scheme, a five-level Er 3+ gain medium, and a four-level Co 2+ Q-switch. The model takes into account cooperative upconversion and excited state absorption (esa) in both the gain and absorber media. Solutions to the rate equations and optimization examples are presented.