We use the worldline formalism to derive master formulas for one-loop N-photon amplitudes in a plane-wave background, both scalar and spinor QED. This generalises previous work by Ilderton Torgrimsson vacuum polarisation case, although with some change methodology since, instead of evaluating path integral on semi-classical trajectory, we special kinematics background uncover crypto-gaussian ch...

We present very sensitive polarimetry of 55 Cnc and τ Boo in an attempt to detect the partially polarised reflected light from the planets orbiting these two stars. 55 Cnc is orbited by a hot Neptune planet (55 Cnc e) at 0.038 AU, a hot Jupiter planet (55 Cnc b) at 0.11 AU, and at least 3 more distant planets. The polarisation of this system is very stable, showing no sign of the periodic varia...

Two-photon fluorescence polarisation and stimulated emission depletion dynamics are investigated in three high two -photon cross-section push-push polyenes: OM62, LP79 and OM77 and compared to the behaviour of a standard fluorophore (rhodamine 6G). Two-photon fluorescence anisotropy measurements (R(0) and Ω) were undertaken using picosecond time-correlated single photon counting (TCSPC). For OM...

The use of statistical estimation theory to boost the metrological performance measurement apparatus is becoming increasingly popular in a wide range applications. Recently, such an approach has been adopted Hong Ou Mandel interferometry, setting new record time delay and polarization measurement. Here, we extend these pioneering experiments telecom unlock full potential information-based combi...

A non-minimal photon-torsion axial coupling in the quantum elec-trodynamics (QED) framework is considered. The geometrical optics in Riemannian-Cartan spacetime is considering and a plane wave expansion of the electromagnetic vector potential is considered leading to a set of the equations for the ray congruence. Since we are interested mainly on the torsion effects in this first report we just...

One of the important goals of the COMPASS experiment is the determination of the gluonic contribution to the spin of the nucleon. By using the photon gluon fusion (PGF) process in polarised deep inelastic scattering direct access to the gluon polarisation can be obtained. The PGF is selected via the detection of open charm or high pT hadron pairs. In 2001 a large part of the experiment had been...

Correlations of the type discussed by EPR in their original 1935 paradox for continuous variables exist for the quadrature phase amplitudes of two spatially separated fields. These correlations were experimentally reported in 1992. We propose to use such EPR beams in quantum cryptography, to transmit with high efficiency messages in such a way that the receiver and sender may later determine wh...

We present a practical method for active phase control on a photonic chip that has immediate applications in quantum photonics. Our approach uses strain-optic modification of the refractive index of individual waveguides, effected by a millimeter-scale mechanical actuator. The resulting phase change of propagating optical fields is rapid and polarization-dependent, enabling quantum applications...

Vacuum birefringence is governed by the amplitude for a photon to flip helicity or polarisation state in an external field. Here we calculate the flip and non-flip amplitudes in arbitrary plane wave backgrounds, along with the induced spacetime-dependent refractive indices of the vacuum. We compare the behaviour of the amplitudes in the low energy and high energy regimes, and analyse the impact...