Paul D. Townsend

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Information encoded on individual quanta will play an important role in our future lives, much as classically encoded digital information does today. Combining quantum information carried by single photons with classical signals encoded on strong laser pulses in modern fibre-to-the-home (FTTH) networks is a significant challenge, the solution to which will(More)
We present a reach-extender for the upstream transmission path of 10Gb/s passive optical networks based on an optimised cascade of two semiconductor optical amplifiers (SOAs). Through careful optimisation of the bias current of the second stage SOA, over 19dB input dynamic range and up to 12dB compression of the output dynamic range were achieved without(More)
An improved quantum key distribution test system operating at clock rates of up to 2GHz using a specially adapted commercially-available silicon single-photon counting module is presented. The use of an enhanced detector has improved the fiber-based quantum key distribution test system performance in terms of transmission distance and quantum bit error rate.
The performance of selected, commercially available InGaAs/InP avalanche photodiodes operating in a photon-counting mode at an incident wavelength of 1.55 microm is described. A discussion on the optimum operating conditions and their relationship to the electric field distribution within the device is presented.
A dynamically reconfigurable TDM-DWDM PON for converged multi-services at the physical layer (10G, 100G and wireless fronthaul) has been demonstrated for the first time implementing end-to-end SDN management of the access and core network elements. OCIS codes: (060.2330) Fiber optics communications; (060.4510) Optical communication
Fibre-to-the-premises (FTTP) has promised to increase the capacity in telecommunications access networks for well over thirty years. While it is widely recognized that optical fibre based access networks will be a necessity in the short to medium term future, its large upfront cost and regulatory issues are pushing many operators to further postpone its(More)
UNLABELLED The incidence of malignant melanoma in the UK is rising. Increased awareness of melanoma has led to an increase in patients presenting with pigmented lesions to their general practitioner (GP) and to pigmented lesion clinics. The sensitivity and specificity of the general practitioner in diagnosing melanoma remains poor. OBJECTIVES A trial was(More)