SEMICONDUCTOR LASERS: Curved grating creates high-brightness surface-emitting DFB laser

摘要

A curved-grating resonator in a semiconductor quantum-well laser design is the basis for a high-brightness surface-emitting distributed-feedback (SE-DFB) laser developed by Alfalight (Madison, WI). Operating at 976 nm, the laser delivers more than 2 W of diffraction-limited power in continuous-wave (CW) operation. Record output power of 73 W from a single emitter has also been demonstrated. Compared to edge-emitting laser diodes, surface-emitting diodes offer reduced manufacturing costs: critical edge-facet cleaving is replaced by noncritical chip dicing; microchannel coolers are replaced by ultracheap copper blocks; critical die alignment to the knife-edge of a heat sink is replaced by noncritical alignment; and post-bar-fabrication coating and testing requirements are replaced by wafer-level coating and probing, respectively.