Design Optimisation of High-Brightness Laser Diodes for External Cavity Operation in the BRIDLE Project

Abstract

-We report on the design aspects of high performance diode lasers for application in highbrightness spectral beam combining and coherent beam combining modules. Key performance trade-offs are identified and potential solutions are explored.

Separate phase-locking and coherent combining of two laser diodes in a Michelson cavity

“…The excitation of these parasitic vertical modes is suppressed by using an optical trap to reduce their modal gain relative to that of the fundamental mode. The RW lasers here employ a 2.4µm wide InGaP waveguide with an InGaAsP OT layer in the n-waveguide, whose position was optimized to give the best trade-off between the near-field width and higher order mode suppression [8]. With a R = 95% reflection on the back facet and a standard anti-reflection (R = 3 %) coating on the front one, the output power of these lasers reaches 0.76 W at 1 A.…”

Self-consistent simulation of high-brightness diode lasers with external optical feedback

“…The next step is to analyse the results by investigating and quantifying this impact on the output beam quality and efficiency. This will be used to optimise the designs of high-brightness lasers to supress and attenuate the propagation of parasitic modes [9]. The challenge for now is to upgrade this model to include coherent coupling between the laser simulator and the external cavity modelling package.…”