We report the first demonstration of polarisation insensitive all-optical wavelength conversion (AOWC) for single wavelength channel 640 Gbit/s return-to-zero differential-phase-shift-keying (RZ-DPSK) signal and 1.28 Tbit/s polarisation multiplexed (Pol-Mux) RZ-DPSK signals using a 100-m polarisation-maintaining highly nonlinear fiber (PM-HNLF) in a polarisation diversity loop configuration. Th...

Recently, many people have found polarisation features in the SCIAMACHY Level-1c spectrum, in the form of jumps. The jumps are found to be caused by the polarisation correction algorithm, which is evidenced by the fact that the jumps occur only when the polarisation correction is switched on, and only at cluster transitions where the integration time changes. We explain the origin of the jumps,...

Abstract Intense THz sources are expected for further progresses in nonlinear science and technology. Liquids like water durable continuously-reusable under intense laser irradiation emission though such studies on from targets so far limited. Polarisation fine control of is demonstrated with a tilted micro-thin flow by the two cross-linearly-polarised femtosecond pulses (800nm, 35fs, transform...

Observation shows that, to a very close approximation, real polarisers and photomultipliers reproduce Malus' Law even at the \single photon" level, giving a sinusoidal variation of \photon" count with polarisation angle. At rst sight, this appears to rule out various realist models of polarisers and detectors, and casts doubt on their ability to explain \paired-photon" EPR experiments. The obse...

In this paper we question the common wisdom that more polarised voters’ opinions imply larger policy polarisation. We analyse a voting model in which the source of the polarisation in voters’ opinions is “correlation neglect”, that is, voters neglect the correlation in their information sources. Our main result shows that such polarisation in opinions does not necessarily translate to policy po...

In this paper the use of a crossed-dipole array is proposed in joint space-time channel estimation for asynchronous multipath DS-CDMA systems. The polarisation diversity offered by such an array, unlike linearly polarised arrays, is shown to provide a better and more consistent estimation which is less sensitive to the signal polarisation. By utilising the polarisation information inherent in t...

Stimulated emission depletion (STED) population and polarisation dynamics are used to determine 40 α the degree of hexadecapole alignment created in ensembles of rhodamine 6G molecules in solution following two-photon excitation. Hexadecapole molecular alignment is an unavoidable consequence of two-photon excitation but is not observed in spontaneous emission. For a single element diagonal tran...

We address the issue of large-order expansions in strong-field QED. Our approach is based on the one-loop effective action encoded in the associated photon polarisation tensor. We concentrate on the simple case of crossed fields aiming at possible applications of high-power lasers to measure vacuum birefringence. A simple next-to-leading order derivative expansion reveals that the indices of re...

The aim of this review paper is to enlighten some recent progresses in quantum optical metrology in the part of quantum efficiency measurements of photo-detectors performed with bi-photon states. The intrinsic correlated nature of entangled photons from Spontaneous Parametric Down Conversion phenomenon has opened wide horizons to a new approach for the absolute measurement of photodetector quan...

The aim of this thesis is to develop sources of photonic entanglement to study both quantum networkingtasks and some of the foundations of quantum physics. To this end, three high-performance sourcesare developed, each of them taking extensively advantage of standard telecom fibre optics components.The first source generates polarization entanglement via deterministic pair separatio...