Professor Ian Walmsley CBE FRS FCGI

Abstract:

We study both experimentally and theoretically the generation of photon pairs by spontaneous four-wave mixing (SFWM) in standard biréfringent optical fibers. The ability to produce a range of two-photon spectral states, from highly correlated (entangled) to completely factorable, by means of cross-polarized biréfringent phase matching, is explored. A simple model is developed to predict the spectral state of the photon pair which shows how this can be adjusted by choosing the appropriate pump bandwidth, fiber length and birefringence. Spontaneous Raman scattering is modeled to determine the tradeoff between SFWM and background Raman noise, and the predicted results are shown to agree with experimental data. © 2009 Optical Society of America.

Abstract:

Full characterization of detectors in the quantum regime is presented. We determine the POVM elements of a photon-number-resolving detector. A method for precise calibration of detector efficiency is demonstrated. © 2009 IEEE.

Abstract:

We present the joint photon-number statistics of a locally photon-subtracted two-mode vacuum squeezed state of light. Comparison to the unsubtracted statistics shows a successful photon subtraction and the expected shift by one photon number. © 2008 Optical Society of America.

Abstract:

We experimentally demonstrate photon pair production in standard single-mode optical fibers via spontaneous four-wave mixing. The process utilizes birefringent phase matching to control the photon pair joint spectral structure. © 2009 Optical Society of America.