Quasiphasematched concurrent nonlinearities in periodically poled KTiOPO_4 for quantum computing over the optical frequency comb

TL;DR

This paper demonstrates the design and experimental realization of a multigrating periodically poled KTiOPO_4 crystal that enables three coincident nonlinear interactions, advancing the development of scalable quantum computing using optical frequency combs.

Contribution

It introduces a novel multigrating periodically poled crystal supporting multiple nonlinear interactions simultaneously for quantum computing applications.

Findings

Successfully achieved three coincident nonlinear interactions in a single crystal.

Enabled second harmonic generation at 780 nm from 1560 nm pump.

Paved the way for scalable quantum computing with optical frequency combs.

Abstract

We report the successful design and experimental implementation of three coincident nonlinear interactions, namely ZZZ ("type-0"), ZYY (type-I), and YYZ/YZY (type-II) second harmonic generation of 780 nm light from a 1560 nm pump beam in a single, multigrating, periodically poled KTiOPO_4 crystal. The resulting nonlinear medium is the key component for making a scalable quantum computer over the optical frequency comb of a single optical parametric oscillator.