Dispersion-based control of modal characteristics for parametric down-conversion in a multimode waveguide

TL;DR

This paper demonstrates a method to control the spatial properties of photon pairs generated in a multimode waveguide by leveraging intermodal dispersion, enabling tailored nonclassical light sources for quantum applications.

Contribution

It introduces a dispersion-based technique to manipulate the modal characteristics of photon pairs in a multimode waveguide, advancing control over nonclassical light.

Findings

Photon pairs generated in fundamental modes via type-II SPDC

Intermodal dispersion used to control spatial characteristics

Characterization of photon beam quality in heralded regime

Abstract

We report generation of near-infrared photon pairs in fundamental spatial modes via type-II spontaneous parametric down-conversion in a periodically poled potassium titanyl phosphate (KTiOPO4) nonlinear waveguide supporting multiple transverse modes. This demonstrates experimentally a versatile scheme for controlling the spatial characteristics of the produced nonclassical light based on exploitation of intermodal dispersion. The down-converted photons are characterized by the measurement of the beam quality factors in the heralded regime.