Tracking nanoscale perturbation in active disordered media

TL;DR

This paper introduces a numerical method leveraging random laser mode sensitivity to detect nanoscale displacements in disordered media, enabling precise localization of perturbations for applications like particle detection.

Contribution

A novel tracking parameter is defined to locate nanoscale perturbations in disordered media using random laser mode analysis, with demonstrated increased precision with more modes.

Findings

Method's precision improves with more lasing modes

Numerical simulations confirm ability to detect nanometer-scale displacements

Potential for single particle detection and monitoring

Abstract

The disorder induced feedback makes random lasers very susceptible to any changes in the scattering medium. The sensitivity of the lasing modes to perturbations in the disordered systems have been utilized to map the regions of perturbation. A tracking parameter, that takes into account the cumulative effect of changes in the spatial distribution of the lasing modes of the system has been defined to locate the region in which a scatterer is displaced by a few nanometers. We show numerically that the precision of the method increases with the number of modes. The proposed method opens up the possibility of application of random lasers as a tool for monitoring locations of nanoscale displacement which can be useful for single particle detection and monitoring.