Ian Walmsley

Abstract:

We present the first quantum tomography of a detector, using as examples an avalanche photodiode and a photon-number resolving detector. The resulting POVM set agrees well with one derived from a model of the detector. © 2008 Optical Society of America.

Abstract:

We demonstrate experimentally the realization of heralded pure photons generation in a birefringent optical fiber. © 2008 Optical Society of America.

Abstract:

We experimentally demonstrate a heralded source of high-purity two-photon NOON states derived from heralded single-photon sources. © 2008 Optical Society of America.

Abstract:

Quantum storage of multiple optical modes affords improved performance for quantum repeaters. We present new analytic and numerical results unifying the scaling of the multimode storage capacity for various memory protocols in artificially broadened ensembles. © 2008 Optical Society of America.

Abstract:

In an experiment reported recently (Mosley et al 2008 Phys. Rev. Lett. 100 133601), we demonstrated that, through group velocity matched parametric downconversion, heralded single photons can be generated in pure quantum states without spectral filtering. The technique relies on factorable photon pair production, initially developed theoretically in the strict collinear regime; focusing-required in any experimental implementation-can ruin this factorability. Here, we present the numerical model used to design our single photon sources and minimize spectral correlations in the light of such experimental considerations. Furthermore, we show that the results of our model are in good agreement with measurements made on the photon pairs and give a detailed description of the exact requirements for constructing this type of source. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.