Phased 2D semiconductor laser array for high coherent output power

摘要

per describes phasing of semiconductor laser arrays placed in an external Talbot cavity for high coherent output power. The external Talbot cavity couples the light between many adjacent lasers such that all lasers operate at the same frequency and phase, resulting in a high power diffraction limited output beam. We first verified the concepts of the Talbot cavity exploiting a simple 1-D Talbot cavity with 20 elements and demonstrated over 600 mW cw total output power in a diffraction limited output beam. In order to fabricate a highly scalable 2-D phased array of lasers, a new type of monolithic 2-D surface emitter was developed for the 2-D Talbot cavity. We have demonstrated 50 W cw output power from a nonphased 2-D monolithic surface emitting laser array with 1500 laser elements. Finally, using a similar 2-D 12 by 12 element surface emitting laser array, we demonstrated 2-D coherence from a compact 2-D Talbot cavity which includes a GaP mass transport lens array, a liquid crystal array and a phase sensing and control system.