Related papers: Twin-photon techniques for fiber measurements
A detailed theoretical analysis of the spatiotemporal mode of a single photon prepared via conditional measurements on a photon pair generated in the process of parametric down-conversion is presented. The maximum efficiency of coupling the…
We present a consistent multimode theory that describes the coupling of single photons generated by collinear Type-I parametric down-conversion into single-mode optical fibers. We have calculated an analytic expression for the fiber…
We investigate the coupling efficiency of parametric downconversion light (PDC) into single and multi-mode optical fibers as a function of the pump beam diameter, crystal length and walk-off. We outline two different theoretical models for…
The dependence of one- and two-photon characteristics of pulsed entangled two-photon fields generated in spontaneous parametric down-conversion on the pump-pulse properties (shape of the pump-pulse spectrum and its internal structure) is…
Our last experimental results on the realization of a measurement-conditional unitary operation at single photon level are presented. This gate operates by rotating by $90^o$ the polarization of a photon produced by means of Type-II…
We examine the modal, spectral, and polarization entanglement properties of photon pairs generated in a nonlinear, periodically poled, two-mode waveguide (1-D planar or 2-D circular) via nondegenerate spontaneous parametric down-conversion.…
We report on the the experimental realization of hyper-entangled two photon states, entangled in polarization and momentum. These states are produced by a high brilliance parametric source of entangled photon pairs with peculiar…
An experimental scheme for preparing a polarization entangled W states from four photons emitted by parametric down-conversion is proposed. We consider two different configurations and a method of improving the yield by using single photon…
We report a controllable method for producing mixed two-photon states via Spontaneous Parametric Down-Conversion with a two-type-I crystal geometry. By using variable polarization rotators (VPRs), one obtains mixed states of various…
We put forward an approach to estimate the amount of bipartite spatial entanglement of down-converted photon states correlated in orbital angular momentum and the magnitude of the transverse (radial) wave vectors. Both degrees of freedom…
We present experimental results on a method to perform polarimetry on ensembles of single photons. Our setup is based on a measurement method known to be optimal for estimating the state of two level systems. The setup has no moving parts…
We study the joint spectral properties of photon pairs generated by spontaneous parametric down-conversion in a one-dimensional nonlinear photonic crystal in a collinear, degenerate, type-II geometry. We show that the photonic crystal…
We introduce an effective numerical method of density matrix determination of fiber coupled single photon generated in process of spontaneous parametric down conversion in type I non-collinear configuration. The presented theory has been…
With exotic propagation properties, optical Airy beams have been well studied for innovative applications in communications, biomedical imaging, micromachining, and so on. Here we extend those studies to the quantum domain, creating quantum…
We study the processes of spontaneous four wave mixing and of third-order spontaneous parametric downconversion in optical fibers, as the basis for the implementation of photon-pair and photon-triplet sources. We present a comparative…
We produce polarization entangled states with variable degree of entanglement for twin photons. Entanglement in polarization is coupled to entanglement in position that produces transverse coincidence interference fringes. We show both…
It is demonstrated a two-photon interfering technique based on polarization-resolved measurements for the simultaneous estimation with the maximum sensitivity achievable in nature of multiple parameters associated with the polarization…
A non-classical light source emitting pairs of identical photons represents a versatile resource of interdisciplinary importance with applications in quantum optics and quantum biology. Emerging research fields, which benefit from such type…
We analyze the rate of two-photon absorption in tapered optical fibers with diameters less than the wavelength of the incident light. The rate of two-photon absorption is shown to be enhanced due to the small mode volume of the tapered…
The process of electron-positron pair production by linearly polarized photons is used as a polarimeter to perform mobile measurement of linear photon polarization. In the limit of high photon energies, omega, the distributions of the…