Characteristics of correlated photon pairs generated in ultracompact silicon slow-light photonic crystal waveguides

Chunle Xiong, Christelle Monat, Matthew J. Collins, Laurent Tranchant, David Petiteau, Alex S. Clark, Christian Grillet, Graham D. Marshall, Michael J. Steel, Juntao Li, Liam Ofaolain, Thomas F. Krauss, Benjamin J. Eggleton

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


We report the characterization of correlated photon pairs generated in dispersion-engineered silicon slow-light photonic crystal waveguides pumped by picosecond pulses. We found that taking advantage of the 15-nm flat-band slow-light window (v g ∼/30), the bandwidth for correlated photon-pair generation in 96-and 196-μm-long waveguides was at least 11.2 nm, while a 396-μm-long waveguide reduced the bandwidth to 8 nm (only half of the slow-light bandwidth due to the increased impact of phase matching in a longer waveguide). The key metrics for a photon-pair source: coincidence to accidental ratio (CAR) and pair brightness were measured to be a maximum 33 at a pair generation rate of 0.004 pair per pulse in a 196-μm-long waveguide. Within the measurement errors, the maximum CAR achieved in 96-, 196-, and 396-μm-long waveguides is constant. The noise analysis shows that detector dark counts, leaked pump light, linear and nonlinear losses, multiple pair generation, and detector jitter are the limiting factors to the CAR performance of the sources.

Original languageEnglish
Article number6157693
Pages (from-to)1676-1683
Number of pages8
JournalIEEE Journal of Selected Topics in Quantum Electronics
Issue number6
StatePublished - 2012
Externally publishedYes

Bibliographical note

Funding Information:
Manuscript received October 25, 2011; revised January 18, 2011; accepted February 17, 2012. This work was supported in part by the Australian Research Council’s Centre of Excellence under Grant CE110001018, Discovery Early Career Researcher Award and Federation Fellowship programs of the Australian Research Council, and by the Faculty of Science, University of Sydney. The silicon waveguide chip was fabricated under the Engineering and Physical Sciences Research Council—U.K. Silicon Photonics Consortium and supported by the European Union Seventh Framework Programme Marie Curie project “OSIRIS.” C. Xiong, M. J. Collins, A. S. Clark, C. Grillet, and B. J. Eggle-ton are with the Centre for Ultrahigh-bandwidth Devices for Optical Systems (CUDOS), the Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, Sydney, N.S.W. 2006, Australia (e-mail:;;;; egg@physics.


  • Nonlinear optics
  • quantum photonics
  • silicon photonic crystal
  • slow light


Dive into the research topics of 'Characteristics of correlated photon pairs generated in ultracompact silicon slow-light photonic crystal waveguides'. Together they form a unique fingerprint.

Cite this