Design of high power low noise polarization insensitive ridge waveguide laser amplifiers

The ridge waveguide structure is proposed to obtain traveling wave polarization insensitive amplifiers with high saturation power and low spontaneous emission factor. A detailed model is presented, based on an accurate electromagnetic analysis of the active waveguide. Thermal effects and first principles calculations of semiconductor characteristics are included. A positive detuning of the operating wavelength with respect to the semiconductor peak gain wavelength is proposed to reduce the dependence of the polarization insensitivity on the operating point. The advantages of ridge waveguide devices with thin active layers operating at high carrier densities are theoretically demonstrated, and a design procedure is outlined. Finally, the model is validated with published experimental data