Toward compact high-efficiency grating couplers for visible wavelength photonics

Joe A. Smith*, Jorge Monroy-Ruz, Pisu Jiang, John G. Rarity, Krishna C. Balram

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

5 Citations (Scopus)

Abstract

Although grating couplers have become the de-facto standard for optical access to integrated silicon photonics platforms, their performance at visible wavelengths, in moderate index contrast platforms such as silicon nitride, leaves significant room for improvement. In particular, the index contrast governs the diffraction efficiency per grating tooth and the resulting overall coupler length. In this work, we develop two approaches to address this problem: a dielectric grating that sums multiple optical modes to increase the overall output intensity; and an embedded metal grating that enhances the attainable refractive index contrast, and therefore reduces the on-chip footprint. We present experimental results that can be developed to realize compact efficient visible wavelength photonic interconnects, with a view toward cryogenic deployment for quantum photonics, where space is constrained and efficiency is critical.

Original languageEnglish
Pages (from-to)3868-3871
Number of pages4
JournalOptics Letters
Volume47
Issue number15
DOIs
Publication statusPublished - 1 Aug 2022

Bibliographical note

Funding Information:
Acknowledgments. We thank A. Murray, M. Cryan, and D. Sahin for valuable suggestions. J.A.S. and J.G.R. were supported by British Council IL6 (352345416) and J.G.R.’s EPSRC Fellowship EP/M024458/1. J.A.S. and J.M.R. were supported by the EPSRC Quantum Engineering CDT EP/L015730/1. J.M.R. was supported by Consejo Nacional de Ciencia y Tecnologia (CONACyT). K.C.B. acknowledges support from the ERC (ERC-StG, SBS 3-5, 758843). Device fabrication was performed using equipment acquired through EPSRC QuPIC EP/N015126/1.

Funding Information:
British Council (352345416); Engineering and Physical Sciences Research Council (EP/L015730/1, EP/M024458/1, EP/N015126/1); Consejo Nacional de Ciencia y Tecnología; European Research Council (ERC-StG, SBS 3-5, 758843). We thank A. Murray, M. Cryan, and D. Sahin for valuable suggestions. J.A.S. and J.G.R. were supported by British Council IL6 (352345416) and J.G.R.'s EPSRC Fellowship EP/M024458/1. J.A.S. and J.M.R. were supported by the EPSRC Quantum Engineering CDT EP/L015730/1. J.M.R. was supported by Consejo Nacional de Ciencia y Tecnologia (CONACyT). K.C.B. acknowledges support from the ERC (ERC-StG, SBS 3-5, 758843). Device fabrication was performed using equipment acquired through EPSRC QuPIC EP/N015126/1.

Publisher Copyright:
© 2022 Optica Publishing Group.

Research Groups and Themes

  • Bristol Quantum Information Institute
  • Photonics and Quantum
  • QETLabs

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