2007/01/01 by Jonas S. Neergaard-Nielsen, J. S. Neergaard-Nielsen, B. Melholt Nielsen +4 · 9 citations
Computer Science · Physics and Astronomy · #Mechanical and Optical Resonators #Quantum Information and Cryptography #Quantum optics and atomic interactions #quant-ph
paper · pdf · doi:10.1364/oe.15.007940
published as Opt. Express 15, 7940-7949 (2007) · 9 pages, 4 figures; minor changes, added reference
openalex publication_date 2007/01/01 · arxiv created 2007/06/05 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Using cavity-enhanced non-degenerate parametric down-conversion, we have built a frequency tunable source of heralded single photons with a narrow bandwidth of 8 MHz, making it compatible with atomic quantum memories. The photon state is 70% pure single photon as characterized by a tomographic measurement and reconstruction of the quantum state, revealing a clearly negative Wigner function. Furthermore, it has a spectral brightness of ~1,500 photons/s per MHz bandwidth, making it one of the brightest single photon sources available. We also investigate the correlation function of the down-converted fields using a combination of two very distinct detection methods; photon counting and homodyne measurement.