# Quasidistribution of phases in Raman process with weak and strong pumps

## TL;DR

This paper investigates the phase quasidistribution in Raman processes under weak and strong pump conditions, revealing nonclassical features and classical behaviors of different modes through a quantum treatment.

## Contribution

It provides a comprehensive quantum analysis of phase distributions in Raman processes, highlighting differences between weak and strong pump regimes and identifying nonclassical phase features.

## Key findings

- Compound Stokes-phonon mode exhibits nonclassical phase features in both regimes.
- Anti-Stokes-phonon mode remains classical and coherence conserving under strong pump.
- Pump-Stokes mode shows quantum behavior similar to classical in certain cases.

## Abstract

Nonclassicality is studied through a quasidistribution of phases for the Raman process under both weak and strong pump conditions. In the former case, the solution is applicable to both resonant and off-resonant Raman processes, while strong classical pump is assumed at resonance. Under weak pump conditions (i.e., in a complete quantum treatment), the phase difference of phases described by single nonclassical modes is required to be filtered to describe a regular distribution function, which is not the case with strong pump. Compound Stokes-phonon mode shows nonclassical features of phases in both weak and strong pumping, which effect is similar to that for compound pump-phonon (Stokes-anti-Stokes) mode with weak (strong) pump. While anti-Stokes-phonon mode is observed to be classical and coherence conserving in strong pump case, pump-Stokes mode shows similar behavior in a special case in quantum treatment.