Abstract

Recently, monolithically integrated master oscillator power amplifiers (M-MOPA) have demonstrated >1-W coherent output from a cascade of single-mode amplifiers and grating output couplers.¹ By integrating the amplifier and grating output coupler into a single active grating (MAG-MOPA), diffraction-limited coherent output power density up to 1 W/cm has been demonstrated,² and up to 4 W/cm has been projected. Diffraction-limited emission without active phase control results from the uniformity of traveling wave power along the active grating, which uniformly saturates the carrier density and index of refraction. Furthermore, the uniformly saturated carrier density leads to optimum noise suppression. The characteristics of the surface-emitting MAG-MOPA are compared with high-power edge-emitting antiguide arrays, which have demonstrated up to 1.5 W of diffraction-limited output.³ Finally, preliminary cw operation of both the MAG-MOPA and antiguide technologies show promise.

© 1991 Optical Society of America