Design, Fabrication, and Characterization of Ta2O5 Photonic Strip Waveguides

TL;DR

This paper reports the design, fabrication, and characterization of Ta2O5 dielectric waveguides optimized for broadband quantum emitter coupling, demonstrating low propagation loss and high coupling efficiency for integrated quantum photonics.

Contribution

It introduces a new platform of Ta2O5-based single-mode waveguides optimized for broadband quantum emitter coupling with promising experimental results.

Findings

Propagation losses below 1.8 dB/mm

Off-chip coupling efficiencies exceeding 57%

Design optimized for broadband (600-800 nm) operation

Abstract

Efficient coupling of single quantum emitters to guided optical modes of integrated optical devices is of high importance for applications in quantum information science as well as in the field of sensing. Here we present the design and fabrication of a platform for on-chip experiments based on dielectric optical single-mode waveguides(Ta2O5 on SiO2). The design of the waveguide is optimized for broadband (600-800 nm) evanescent coupling to a single quantum emitter (expected efficiency: up to 36%) and efficient off-chip coupling to single-mode optical fibers using inverted tapers. First test samples exhibit propagation losses below 1.8 dB/mm and off-chip coupling efficiencies exceeding 57%. These results are promising for efficient coupling of solid state quantum emitters like NV- and SiV-centers to a single optical mode of a nanoscale waveguide.