Geneartion of higher dimensional modal entanglement using a three waveguide directional coupler

TL;DR

This paper presents a method to generate higher-dimensional modal entanglement using a three waveguide directional coupler in lithium niobate, enabling control over photon spatial modes for advanced quantum applications.

Contribution

It introduces a novel design approach for a three waveguide coupler to produce higher-dimensional entangled photon states via type II spontaneous parametric down conversion.

Findings

Achieved control over three spatial modes for entangled photon pairs.

Demonstrated the design flexibility of the waveguide structure.

Enabled generation of higher-dimensional entanglement in integrated photonics.

Abstract

In this paper, we propose a method for the generation of higher dimensional modal entanglement through type II spontaneous parametric down conversion process using a three waveguide directional coupler in a periodically poled lithium niobate substrate. We show that by a proper design, it is possible to achieve an output state of two photons occupying three different spatial modes. The advantage of using such waveguide structure is its flexibility and the design space availability to achieve desired characteristics of the photon pairs generated in the down conversion process