Parity-time Symmetric gratings in 1550 nm Distributed-Feedback lasers diodes: insight on device design rules

H. Benisty (1) , Vincent Brac de La Perrière (2) , Abderahim Ramdane (2) , Anatole Lupu (2)

1 Laboratoire Charles Fabry / Nanophotonique
2 C2N - Centre de Nanosciences et de Nanotechnologies

We build up on former results from our work on parity-time symmetric gratings implemented in 1550 nm distributed feedback laser diodes to address the design issues raised by the first observed trends. These laser diodes are of "complex-coupled" nature, with modulations of both real and imaginary part of effective index, with relative phase π2 related to the parity-time symmetry. The unidirectionality of the photonic behavior in reflection mode is dependent on the level of extra losses incurred by the metallic grating used to implement fixed loss modulation onto a nearly uniform gain, either as a first order or as a third order grating. The observed behavior suggests that facets play a large role in setting the desired "unidirectional" lasing operation points, with preferential emission on one side. We explore this issue, of generic interest for the coupling of parity-time symmetric structures to open space.

Domaines: Optique [physics.optics]

H. Benisty, Vincent Brac de La Perrière, Abderahim Ramdane, Anatole Lupu. Parity-time Symmetric gratings in 1550 nm Distributed-Feedback lasers diodes: insight on device design rules. Journal of the Optical Society of America B, In press, 38 (9), pp.C168. ⟨10.1364/JOSAB.428638⟩. ⟨hal-03284234⟩