Cavity-enhanced narrow bandwidth photon pairs generation at the telecom wavelength with a triple resonance configuration

TL;DR

This paper reports a novel cavity-enhanced, narrow bandwidth photon pair source at telecom wavelengths using a triple resonance optical parametric oscillator, suitable for long-distance quantum communication.

Contribution

The work introduces a triple resonance cavity design for efficient, narrow bandwidth photon pair generation at telecom wavelengths, advancing quantum communication technologies.

Findings

Photon pairs at 1560 nm with 8 MHz bandwidth

Photon pair generation rate of 134 s-1MHz-1mW

Coherence time of 27.7 ns

Abstract

In this paper, we present a narrow bandwidth source at the telecom wavelength based on type II PPKTP crystal inside an optical cavity. Simultaneous resonances of the pump and the two down-converted fields are achieved by special design of the cavity. This is a triple resonances optical parametric oscillator (OPO) far below threshold, which generates photon pairs at around 1560 nm with a bandwidth of 8 MHz. A coherence time of 27.7 ns is estimate by a time correlation measurement, and the estimated photon pairs generating rate is 134 s-1MHz-1mW-1. As entangled photon pairs in the telecom regime is suitable for long distance transmission and manipulation, this source is desirable for the demands of quantum communication.