External-to-cavity lateral-mode harnessing devices for high-brightness broad-area laser diodes. Concept, realizations and perspectives

摘要

An external linear optical system (with no feedback to the laser) converts the laser's multimode emission into a multi-longitudinal but spatially single-mode (diffraction-limited) spot. Recent progress in laser diode mode analysis demonstrating the high stability of the mode pattern of broad-area laser diodes and the development of the low-loss high-spectral-resolution phase modulator are the key enablers of such a technique. These advancements led to the demonstration of 60% conversion efficiency of multimode 980 nm diode-laser emissions into a single-mode fiber.