Heat Evacuation from Active Raman Media Heat Evacuation from Active Raman Media Using Quasi-PT Symmetry Coupling

TL;DR

This paper introduces a novel quasi-PT symmetry coupling method using a coupled-waveguide structure to significantly reduce heat generated by anti-Stokes Raman scattering in active Raman media, enhancing thermal management.

Contribution

It presents a new frequency-selective quasi-PT symmetry approach with coupled waveguides to suppress heat from CARS in active Raman media, which was not previously demonstrated.

Findings

Heat reduction by up to five times with optimal coupling.

Effective suppression of reversed CARS cycles.

Enhanced thermal management in Raman systems.

Abstract

We propose to use frequency-selective quasi parity-time symmetry to reduce the heat generated by coherent anti-Stokes Raman scattering (CARS) reversed cycles in active Raman media with phase mismatch. This is accomplished using a coupled-waveguide structure, which includes the active Raman waveguide (RW), where the Stokes signal undergoes amplification via stimulated Stokes Raman scattering (SSRS), and a dissipative waveguide (DW), which is tuned to the anti-Stokes wavelength so as to evacuate the corresponding anti-Stokes photons from the RW by coupling. The DW introduces optical loss that partially offsets the growth of the anti-Stokes signal in the RW and hence suppress the reversed CARS cycles that would otherwise result into heat generation in the RW. It is shown that the frequency-selective quasi parity-time symmetry provided by the DW can reduce the heat in active Raman media by a very factor of up to five when the CARS phase mismatch is compensated for by the optimum level of coupling between the RW and the DW.