Open-loop wavelength selective external resonator and beam combining system

Abstract

A variety of dense wavelength beam combining (DWBC) apparatuses are described herein that combine a plurality of individual input beams into a single output beam. DWBC apparatuses contemplated herein are open-loop configurations, i.e. configurations where the wavelength selective optics of a feedback generation system are decoupled from a beam combining system that combines a plurality of input beams each having a wavelength selected from a range of different wavelengths. Specifically, each constituent beam of the combined output beam produced by the beam combining system traverses an optical path that does not include the wavelength-selective optics of the feedback generation system. DWBC apparatuses contemplated herein further provide for matching the wavelength-dependent angular dispersion functions of optics of the feedback generation system with the wavelength-dependent angular dispersion functions of optics of the beam combining system. The external cavity laser diode array comprises edge-emitting LD (111A-111N), a focussing optics (112) for divergence control of the emitted beams onto diffracting optics (115), a retroreflector (120) and a half-wave plate (113) and a polarizer (114) for control of the output power. An intra-cavity spatial filter (116) may be used to control the spatial beam quality and an extra-cavity dispersive optics (122) for delivering a combined multi-wavelength high power beam.

Description

technical field [0001] The present disclosure relates generally to laser systems, and more particularly to systems and methods for narrow bandwidth laser beam stabilization and multiple laser beam combining. Background technique [0002] Dense Wavelength Beam Combining (DWBC) technology enables multiple relatively low power input beams to be spatially superimposed to produce a single high power output beam. To ensure high-power output beam quality, DWBCs require wavelength locking of each individual emitter. Wavelength locking refers to forcing the vast majority of radiation emitted by an emitter to have wavelengths that fall within a narrow spectrum of desired wavelengths. The DWBC system achieves wavelength locking of each individual transmitter by providing wavelength selective feedback. Wavelength selective feedback stimulates the emission of radiation at desired wavelengths, which excludes radiation at undesired wavelengths. DWBC systems can utilize resonator cavitie...

AI Technical Summary

Problems solved by technology

However, spatial filtering is a lossy procedure that can cause a significant reduction in the efficiency of the DWBC system

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