Bullseye dielectric cavities for photon collection from a surface-mounted quantum-light-emitter

• Published in: Scientific reports Vol. 13; no. 1; p. 5316
• Main Authors: Hekmati, Reza, Hadden, John P., Mathew, Annie, Bishop, Samuel G., Lynch, Stephen A., Bennett, Anthony J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 31.03.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/399/1098; 639/766/483/3925; Aperture; Cavities; Design; Efficiency; Gold; Humanities and Social Sciences; Light; multidisciplinary; Optics; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-32359-0

Coupling light from a point source to a propagating mode is an important problem in nano-photonics and is essential for many applications in quantum optics. Circular “bullseye” cavities, consisting of concentric rings of alternating refractive index, are a promising technology that can achieve near-unity coupling into a first lens. Here we design a bullseye structure suitable for enhancing the emission from dye molecules, 2D materials and nano-diamonds positioned on the surface of these cavities. A periodic design of cavity, meeting the Bragg scattering condition, achieves a Purcell factor of 22.5 and collection efficiency of 80%. We also tackle the more challenging task of designing a cavity for coupling to a low numerical aperture fibre in the near field. Finally, using an iterative procedure, we study how the collection efficiency varies with apodised (non-periodic) rings.