Pump-induced Exceptional Points in Lasers

TL;DR

This paper explores how nonuniform pumping in lasers induces exceptional points that can drastically alter lasing behavior, including turning the laser off despite increased pump power, with experimental verification possible in coupled microdisk lasers.

Contribution

It introduces the concept of pump-induced exceptional points in lasers and demonstrates their impact on laser dynamics and potential experimental observation.

Findings

Exceptional points can be induced by nonuniform pumping in lasers.

Near these points, lasers may turn off despite increased pump power.

Experimental setups with coupled microdisk lasers can probe these phenomena.

Abstract

We demonstrate that the above-threshold behavior of a laser can be strongly affected by exceptional points which are induced by pumping the laser nonuniformly. At these singularities, the eigenstates of the non-Hermitian operator which describes the lasing modes coalesce. In their vicinity, the laser may turn off even when the overall pump power deposited in the system is increased. Such signatures of a pump- induced exceptional point can be experimentally probed with coupled ridge or microdisk lasers.