Semiclassical Analysis of Spectral Singularities and Their Applications in Optics

TL;DR

This paper introduces a semiclassical method to analyze spectral singularities in optical systems, revealing their stability and providing bounds on gain decay for lasing in slab media.

Contribution

The authors develop a novel semiclassical approach to compute spectral singularities and analyze their stability in optical gain media with decaying pump intensity.

Findings

Universal upper bounds on decay constants for lasing

Spectral singularity wavelengths are stable against decay variations

Spectral singularities demonstrate robustness in optical systems

Abstract

Motivated by possible applications of spectral singularities in optics, we develop a semiclassical method of computing spectral singularities. We use this method to examine the spectral singularities of a planar slab gain medium whose gain coefficient varies due to the exponential decay of the intensity of pumping beam inside the medium. For both singly- and doubly-pumped samples, we obtain universal upper bounds on the decay constant beyond which no lasing occurs. Furthermore, we show that the dependence of the wavelength of the spectral singularities on the value of the decay constant is extremely mild. This is an indication of the stability of optical spectral singularities.