Poling-free Spontaneous Parametric Down Conversion without for Silicon Carbide and Lithium Niobate photonics

TL;DR

This paper introduces a novel device architecture enabling spontaneous parametric down-conversion (SPDC) without periodic poling, broadening material platform options and simplifying fabrication for quantum photonics.

Contribution

It presents a mode conversion-based design for phase-matched SPDC that works in silicon carbide and lithium niobate, eliminating the need for periodic poling.

Findings

Designs for SPDC in Silicon Carbide on-insulator and Lithium Niobate on-insulator.

Enables CMOS-compatible SPDC without periodic poling.

Simplifies fabrication and broadens material platform options.

Abstract

State-of-the-art photon sources based on spontaneous parametric down-conversion (SPDC) currently rely on artificial structuring of the material nonlinearity to satisfy phase-matching conditions. This technique, known as periodic poling, is available only in a limited number of material platforms and introduces additional fabrication steps and errors, which are detrimental to up-scaling efforts. Here, we present a device architecture that enables SPDC of a wide range of frequencies without the need for periodic poling. We present explicit designs and calculations for 4H Silicon Carbide on-insulator, in which SPDC photon generation is so far unavailable, and thin-film Lithium Niobate on-insulator, a state-of-the-art quantum photonics platform. Our design, based on mode conversion and subsequent modal phase-matched SPDC, facilitates a CMOS compatible $\chi^{(2)}$ platform, and simplifies photon sources by removing the requirement of periodic poling and the associated additional fabrication complexity.