Coherent control of photon pairs via quantum interference between second- and third-order quantum nonlinear processes

TL;DR

This paper demonstrates a novel all-optical method for coherently controlling photon pairs by exploiting quantum interference between second- and third-order nonlinear processes in integrated photonics, enabling phase-dependent modulation of biphoton states.

Contribution

It introduces an all-optical approach to coherently control biphoton states through interference of different order nonlinear processes, a new form of quantum control in nonlinear optics.

Findings

Phase-dependent modulation of photon pair generation rate.

Spectral shaping of biphoton wavefunctions.

Interference between different order nonlinear processes enables quantum control.

Abstract

Genuine quantum interference between independent nonlinear processes of different order provides a route to coherent control that cannot be reduced to a classical field interference. Here we present an all-optical analogue of coherent carrier injection by exploiting interference between second- and third-order quantum nonlinear processes in an integrated photonic platform. Photon pairs generated via spontaneous parametric down-conversion and spontaneous four-wave mixing coherently contribute to the same final two-photon state, resulting in a phase-dependent modulation of both the generation rate and the spectral structure of the emitted biphoton state. We illustrate the features of such interference and how it can be used to shape biphoton wavefunctions and their quantum correlations. These results identify interference between nonlinear processes of different order as a distinct form of coherent quantum control within quantum nonlinear optics.