Creation of New Lasing Modes with Spatially Nonuniform Gain

TL;DR

This paper demonstrates through numerical analysis that spatially nonuniform gain distributions in a 1D random structure can create new lasing modes with unique frequencies and high directionality, significantly altering lasing properties.

Contribution

It introduces a novel method of generating new lasing modes by spatially nonuniform gain, expanding the understanding of random lasing behavior without mode competition.

Findings

New lasing modes appear between existing modes with uniform gain.

These modes exhibit high output directionality.

Lasing properties can be significantly modified without structural changes.

Abstract

We report on the creation of new lasing modes with spatially nonuniform distributions of optical gain in a one-dimensional random structure. It is demonstrated numerically that even without gain saturation and mode competition, the spatial nonuniformity of gain can cause dramatic and complicated changes of lasing modes. New modes appear with frequencies in between those of the lasing modes with uniform gain. We examine some new lasing modes in detail and find they exhibit high output directionality. Our results show that the random lasing properties may be modified significantly without changing the underlying structures.