Lifetime and Polarization for Real and Virtual Correlated Stokes-anti-Stokes Raman Scattering in Diamond

TL;DR

This study investigates the polarization and temporal correlations of correlated Stokes and anti-Stokes photon pairs in diamond, revealing fundamental differences between real and virtual phonon-mediated processes through decay rates and a phenomenological model.

Contribution

It provides the first detailed comparison of real and virtual SaS processes in diamond, highlighting their polarization characteristics and decay dynamics.

Findings

Real SaS process governed by phonon lifetime of ~2.8 ps.

Virtual SaS process occurs within ~0.2 ps, limited by laser pulse width.

Phenomenological model explains differences based on phonon creation and decay probabilities.

Abstract

The production of correlated Stokes (S) and anti-Stokes (aS) photons (SaS process) mediated by real or virtual phonon exchange has been reported in many transparent materials. In this work, we investigate the polarization and time correlations of SaS photon pairs produced in a diamond sample. We demonstrate that both S and aS photons have mainly the same polarization of the excitation laser. We also perform a pump-and-probe experiment to measure the decay rate of the SaS pair production, evidencing the fundamental diference between the real and virtual (phonon exchange) processes. In real processes, the rate of SaS pair production is governed by the phonon lifetime of $(2.8 \pm 0.3)$ ps, while virtual processes only take place within the time width of the pump laser pulses of approximately 0.2 ps. We explain the diference between real and virtual SaS processes by a phenomenological model, based on probabilities of phonon creation and decay.