This paper describes our work on the realization of a non-hermitian Hamiltonian system in time-delay coupled semiconductor lasers consisting of two identical lasers, operated with a small frequency detuning between them, and bidirectionally coupled to each other through optical injection. The effective Hamiltonian for this system is non-hermitian, and, under some assumptions and conditions, reminiscent of two-site paritytime (PT) symmetric Hamiltonians, a topic that is under intense investigation. The dynamical response of the intensity of the lasers as a function of the detuning between them reveals characteristics of a PT symmetric system, and our emphasis is on the features that arise from the delayed coupling. Experimental measurements are in good agreement with numerical simulation of the nonlinear rate equation model that describes the coupled system.

Date Published: 5 September 2019
PDF: 14 pages
Proc. SPIE 11081, Active Photonic Platforms XI, 110810G (5 September 2019); doi: 10.1117/12.2523786

Published in SPIE Proceedings Vol. 11081:
Active Photonic Platforms XI
Ganapathi S. Subramania; Stavroula Foteinopoulou, Editor(s)