Abstract

We propose a novel physical mechanism based on periodic non-Hermitian potentials to efficiently control the complex spatial dynamics of broad-area lasers, particularly in vertical-cavity surface-emitting lasers (VCSELs), achieving a stable emission of maximum brightness. A radially dephased periodic refractive index and gain-loss modulations accumulate the generated light from the entire active layer and concentrate it around the structure axis to emit narrow, bright beams. The effect is due to asymmetric inward radial coupling between transverse wave vectors for particular phase differences of the refractive index and gain-loss modulations. Light is confined into a central beam with large intensity, opening the path to design compact, bright, and efficient broad-area light sources. We perform a comprehensive analysis to explore the maximum central intensity enhancement and concentration regimes. This Letter reveals that the optimum schemes are those holding unidirectional inward coupling, but not fulfilling a perfect local PT-symmetry.

© 2019 Optical Society of America

Non-Hermitian spectral changes in the scattering of partially coherent radiation by periodic structures

P. A. Brandão and S. B. Cavalcanti
Opt. Lett. 44(17) 4363-4366 (2019)

GaSb-based vertical-cavity surface-emitting lasers with an emission wavelength at 3 μm

Alexander Andrejew, Stephan Sprengel, and Markus-Christian Amann
Opt. Lett. 41(12) 2799-2802 (2016)

Non-Hermitian topological phase transition in PT-symmetric mode-locked lasers

Stefano Longhi
Opt. Lett. 44(5) 1190-1193 (2019)

Stabilization of broad-area semiconductor laser sources by simultaneous index and pump modulations

Waqas Waseem Ahmed, Shubham Kumar, Judith Medina, Muriel Botey, Ramon Herrero, and Kestutis Staliunas
Opt. Lett. 43(11) 2511-2514 (2018)

Temporal localized structures in mode-locked vertical external-cavity surface-emitting lasers

P. Camelin, C. Schelte, A. Verschelde, A. Garnache, G. Beaudoin, I. Sagnes, G. Huyet, J. Javaloyes, S. V. Gurevich, and M. Giudici
Opt. Lett. 43(21) 5367-5370 (2018)