Christoph Marquardt

TL;DR: In this article, the polarization sector of a bright polarization squeezed beam was reconstructed from a complete set of Stokes measurements using the unique SU(2) Wigner distribution to represent states.

TL;DR: It is experimentally demonstrate that heterodyne detection outperforms homodyne Detection for almost all Gaussian states, the details of which depend on the squeezing strength and thermal noise.

Abstract: We demonstrate a method to perform spectroscopy of near-infrared single photons without the need of dispersive elements. This method is based on a photon energy resolving transition edge sensor and is applied for the characterization of widely wavelength tunable narrow-band single photons emitted from a crystalline whispering gallery mode resonator. We measure the emission wavelength of the generated signal and idler photons with an uncertainty of up to 2 nm.

TL;DR: A demonstration of ``cryptographic agility'' in quantum communications offers a robust way to adapt security protocols in the face of a novel attack.

TL;DR: In this paper, the authors used a compact crystalline whispering gallery mode resonator made of lithium niobate as a degenerate parametric oscillator for nonclassical light.