Triangular Quantum Photonic Devices with Integrated Detectors in Silicon Carbide

TL;DR

This paper presents a novel triangular SiC photonic device with integrated detectors, achieving high emission coupling efficiency and demonstrating the fabrication and characterization of NbTiN thin films on SiC for quantum photonic applications.

Contribution

It introduces a new triangular SiC waveguide design with integrated SNSPDs and reports the first sputtering of NbTiN on 4H-SiC, along with optimized detection geometries.

Findings

Maximum coupling efficiency of 89% into the optical mode.

High coupling efficiency (>75%) in over half of configurations.

NbTiN thin films on SiC show similar transport properties to those on SiO2.

Abstract

Triangular cross-section SiC photonic devices have been studied as an efficient and scalable route for integration of color centers into quantum hardware. In this work, we explore efficient collection and detection of color center emission in a triangular cross-section SiC waveguide by introducing a photonic crystal mirror on its one side and a superconducting nanowire single photon detector (SNSPD) on the other. Our modeled triangular cross-section devices with a randomly positioned emitter have a maximum coupling efficiency of 89 % into the desired optical mode and a high coupling efficiency (> 75 %) in more than half of the configurations. For the first time, NbTiN thin films were sputtered on 4H-SiC and the electrical and optical properties of the thin films were measured. We found that the transport properties are similar to the case of NbTiN on SiO2 substrates, while the extinction coefficient is up to 50 % higher for 1680 nm wavelength. Finally, we performed Finite-Difference Time-Domain simulations of triangular cross-section waveguide integrated with an SNSPD to identify optimal nanowire geometries for efficient detection of light from TE and TM polarized modes.