Telecom-band Multi-Type Spontaneous Parametric Downconversion in Periodically Polarized Nonlinear Materials

TL;DR

This paper analyzes various quasi-phase-matching processes in periodically polarized nonlinear materials for spontaneous parametric downconversion, introduces a general method for multiple quasi-phase-matching types, and proposes a novel entangled photon pair source for telecom applications.

Contribution

It presents a comprehensive analysis of quasi-phase-matching in nonlinear materials and introduces a new design for generating multiple entangled photon pairs in the telecom band.

Findings

Multiple quasi-phase-matching processes are characterized and calculated.

A general method for achieving various quasi-phase-matching types is proposed.

A novel Sagnac interferometer-based design for entangled photon pairs in the telecom band is discussed.

Abstract

Spontaneous parametric downconversion is an essential technique in quantum optics experiments. In this paper, various quasi-phase-matching processes in several typical periodically polarized nonlinear materials are analyzed and calculated. Furthermore, a general method for realizing multiple types of quasi-phase-matching in a monolithic material is presented. Finally, a novel design to prepare multiple entangled photon pairs based on the Sagnac interferometer is discussed. This technology can be applied to tiny optical paths in the telecom C band, saving both cost and space.