Role of seeding the cavity of a two-photon correlated emission laser with thermal light

TL;DR

This paper investigates how seeding a two-photon correlated emission laser cavity with thermal light affects its quantum properties, revealing initial spoilage of nonclassical features that diminish over time, with implications for practical quantum light sources.

Contribution

It provides a detailed analysis of the impact of thermal seeding on two-photon emission lasers, highlighting the temporal evolution of squeezing, entanglement, and intensity.

Findings

Seeding with thermal light initially reduces nonclassical features.

The mean photon number exhibits a dip or peak depending on the seeding mode.

Nonclassical features diminish over time due to emission-absorption mechanisms.

Abstract

A study of the evolution of two-mode squeezing, entanglement and intensity of the cavity radiation of a two-photon correlated emission laser initially seeded with a thermal light is presented. The dependence of the degree of two-mode squeezing and entanglement on the intensity of the thermal light and time is found to have more or less a similar nature, although the actual values differ specially in the early stages of the process and when the atoms are initially prepared in nearly 50:50 probability to be in the upper and lower energy levels. Particularly, seeding the cavity turns out to spoil the nonclassical features significantly in the vicinity of $t=0$. It is also shown that the mean photon number in a wider time span has a dip when mode $b$ is seeded, but a peak when mode $a$ is seeded. Moreover, this study asserts that the effect of the seeded light on the nonclassical features and intensity of the cavity radiation is eroded with time by the pertinent emission-absorption mechanism which can be taken as an encouraging sign in practical utilization of this quantum system as a source of bright entangled light.