Enhanced zero-phonon line emission from an ensemble of W centers in circular and bowtie Bragg grating cavities

Date

2024-11-19

Department

Program

Citation of Original Publication

Veetil, Vijin Kizhake, Junyeob Song, Pradeep N. Namboodiri, Nikki Ebadollahi, Ashish Chanana, Aaron M. Katzenmeyer, Christian Pederson, et al. “Enhanced Zero-Phonon Line Emission from an Ensemble of W Centers in Circular and Bowtie Bragg Grating Cavities.” Nanophotonics, November 19, 2024. https://doi.org/10.1515/nanoph-2024-0485.

Rights

This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
Public Domain

Abstract

Color centers in silicon have recently gained considerable attention as single-photon sources and as spin qubit-photon interfaces. However, one of the major bottlenecks to the application of silicon color centers is their low overall brightness due to a relatively slow emission rate and poor light extraction from silicon. Here, we increase the photon collection efficiency from an ensemble of a particular kind of color center, known as W centers, by embedding them in circular Bragg grating cavities resonant with their zero-phonon-line emission. We observe a ≈5-fold enhancement in the photon collection efficiency (the fraction of photons extracted from the sample and coupled into a single-mode fiber), corresponding to an estimated ≈11-fold enhancement in the photon extraction efficiency (the fraction of photons collected by the first lens above the sample). For these cavities, we observe lifetime reduction by a factor of ≈1.3 . For W centers in resonant bowtie-shaped cavities, we observed a ≈3-fold enhancement in the photon collection efficiency, corresponding to a ≈6-fold enhancement in the photon extraction efficiency, and observed a lifetime reduction factor of ≈1.1 . The bowtie cavities thus preserve photon collection efficiency and Purcell enhancement comparable to circular cavities while providing the potential for utilizing in-plane excitation methods to develop a compact on-chip light source.