High order Coherence Functions and Spectral Distributions as given by the Quantum Theory of Laser Radiation

TL;DR

This paper introduces a method to measure the time evolution of off-diagonal elements of the laser's density matrix, providing experimental validation of quantum theory predictions on decay rates and spectral properties.

Contribution

It presents a novel experimental technique for measuring higher-order coherence functions and spectral distributions in laser radiation, confirming quantum theory predictions.

Findings

Decay rates of off-diagonal elements for k=2,3 measured for the first time

Measured decay rates agree with quantum theory

Spectral linewidths correspond to off-diagonal decay rates

Abstract

We propose and demonstrate a method for measuring the time evolution of the off-diagonal elements $\rho_{n,n+k}(t)$ of the reduced density matrix obtained from the quantum theory of the laser. The decay rates of the off-diagonal matrix element $\rho_{n,n+k}(t)$ (k=2,3) are measured for the first time and compared with that of $\rho_{n,n+1}(t)$, which corresponds to the linewidth of the laser. The experimental results agree with the quantum theory of the laser.