Boosting the output power of large-aperture lasers by breaking their circular symmetry
Brejnak, A.; Gębski, M.; Sokół, A. K.; Marciniak, M.; Wasiak, M.; Muszalski, J.; Lott, J. A.; Fischer, I.; Czyszanowski, T.
Optica 8 (9), 1167-1175 (2021)
Breaking the spatial symmetry in optical systems has become a key approach to the study of nonlinear dynamics, wave chaos, and non-Hermitian physics. Moreover, it enables tailoring of the spatiotemporal properties of such systems. Breaking the circular symmetry of lasers yields a more uniform light intensity profile within the optical aperture and makes uniform the spectral distribution of the optical states (modes). Those effects are known to enhance spontaneous as well as stimulated emission and consequently suppress undesired nonradiative recombination in the active region, but their importance for laser emission is not fully understood so far. In this paper, using the example of vertical-cavity surface-emitting lasers, we show that intentionally deformed optical apertures induce a more uniform light intensity distribution within the optical aperture, related to wave chaos, and a higher density of optical states, enhancing stimulated emission as predicted by quantum electrodynamics theory. These two phenomena contribute to increasing the optical output power by more than 60% and quantum efficiency by more than 10%. The results of this study are of significant importance for a variety of lasers, showing a clear link between the fundamentals of their operation and quantum electrodynamics and providing a general, robust method of enhancing emitted power for high-power broad-area lasers.