Phase-locked arrays of semiconductor diode lasers

Semiconductor diode lasers can be combined into monolithic phase-locked arrays that operate to continuous-wave (CW) powers in excess of 1 W and exhibit well-defined output beams to hundreds of mW. Applications of arrays include high-speed optical recording, high-speed printing, free-space communications, and efficient pumping of solid-state lasers. The authors review the current state of phase-locked array design with emphasis on the means for achieving fundamental mode operation. Models for understanding and predicting the behavior of phase-locked arrays are discussed, and the potential of various array structures to operate in a single, diffraction-limited output beam is evaluated.