Ultra-Bright Single Photon Source Based on Cavity-coupled Diamond Color Center

ABSTRACT: Physical Sciences Inc. (PSI) proposes to develop a single-photon source based on a diamond nano-crystal coupled to a Fabry-Perot micro-cavity. Defects in crystalline diamond have demonstrated excellent single photon properties with g^(2)(0)<0.1. Our diamond nano-crystal will contain a single Chromium-based defect capable of producing single-photons in the two near-IR transparency windows (740-760 nm and 770-785 nm). Chromium defects are uniquely suited for this application due to their emission wavelength, two-level energy structure, narrow natural emission (full-width half-max ~ 7 nm), short lifetimes (~2 ns), and compatibility with the atomic line filter currently under development by PSI. By coupling a single nano-crystal to an optical micro-cavity in the strong-Purcell regime, the linewidth of the single-photon emission can be narrowed to 1 GHz with emission jitter of ~ 100 ps, enabling unconditionally secure, free-space quantum communication. In the Phase I program, PSI will develop and characterize the single-photon source and micro-cavity independently and as a coupled system. The innovative single photon source developed in this program will enable improved secure key data rates and increased security for quantum key distribution. BENEFIT: Quantum communication promises an unconditionally secure method for information transfer. True single photon sources are necessary to assure security and can operate up to 10x faster than attenuated laser pulses. Military, financial, medical and other institutions with sensitive data will benefit from practical improvements to quantum communications links. PSI envisions ending Phase II with a production-ready SPS prototype and envisions producing complete SPS units to sell independently and as partner products to our atomic line filters (ALFs).