Self-adjustment of a nonlinear lasing mode to a pumped area in a two-dimensional microcavity

TL;DR

This study uses numerical simulations based on the Maxwell-Bloch model to show how a nonlinear lasing mode in a two-dimensional microcavity self-adjusts its pattern to the pumped region, breaking symmetry and forming stable rotating-wave solutions.

Contribution

It introduces a nonlinear dynamical mechanism explaining how lasing modes adapt their spatial pattern to the pumped area in a microcavity, including asymmetric mode formation.

Findings

Asymmetric lasing modes violate cavity mirror symmetries.

Rotating-wave components form stable stationary solutions.

Different locking rules observed for uniform vs. selective pumping.

Abstract

We numerically performed wave dynamical simulations based on the Maxwell-Bloch (MB) model for a quadrupole-deformed microcavity laser with spatially selective pumping. We demonstrate the appearance of an asymmetric lasing mode whose spatial pattern violates both the x- and y-axes mirror symmetries of the cavity. Dynamical simulations revealed that a lasing mode consisting of a clockwise or counterclockwise rotating-wave component is a stable stationary solution of the MB model. From the results of a passive-cavity mode analysis, we interpret these asymmetric rotating-wave lasing modes by the locking of four nearly degenerate passive-cavity modes. For comparison, we carried out simulations for a uniform pumping case and found a different locking rule for the nearly degenerate modes. Our results demonstrate a nonlinear dynamical mechanism for the formation of a lasing mode that adjusts its pattern to a pumped area.