Walk-off effects, originating from the difference between the group and phase velocities, limit the efficiency of nonlinear optical interactions. While transverse walk-off can be eliminated by proper medium engineering, longitudinal walk-off is harder to avoid. In particular, ultrafast twin-beam generation via pulsed parametric down-conversion and four-wave… (More)
— In this paper we report our systematic study of a promising absolute calibration technique of analog photo-detectors, based on the properties of parametric down conversion. Our formal results and a preliminary uncertainty analysis show that the proposed method can be effectively developed with interesting applications to metrology. I. INTRODUCTION In… (More)
—We propose a new scheme for measuring the quantum efficiency of photon counting detectors by using correlated pho-tons. The measurement technique is based on a 90 rotation of the polarization of one photon member of a correlated pair produced by parametric down-conversion, conditioned on the detection of the other correlated photon after polarization… (More)
We proposed the procedure of measuring the unknown state of the three-level system – the qutrit, which was realized as the arbitrary polarization state of the single-mode biphoton field. This procedure is accomplished for the set of the pure states of qutrits; this set is defined by the properties of SU(2) transformations, that are done by the polarization… (More)
Researchers characterize the multiple ways of entanglement that exist between different frequency bands in a down-converted frequency comb. Entanglement underlies all of quantum information science. It is most familiar as a relation between two parts of a single system, in which the properties of each part—taken separately—are uncertain but at the same time… (More)
We discuss the fundamental problems of nonclassical correlations and microscopic entanglement experimental observation possibility for multiphoton quantum light beams. Optical beams of multiphoton nonclassical light are of practical interest due to possibility of applications in quantum metrology and quantum informatics. Quantum macroscopic states of light… (More)
Two-Photon Spectral Amplitude of entangled states is engineered to produce a losslessly decomposition in non-overlapping single Schmidt modes. The method relies on spontaneous parametric down-conversion pumped by a comb-like spectrum radiation.
The intensity correlation function of squeezed vacuum, produced in an OPA, was measured with a photon-number resolving multi-pixel detector (MPPC). Based on realistic MPPC model, strong photon bunching was revealed for low-gain OPA radiation.
The goal of this research is to determine and study a physical system that will enable a fast and intrinsically two-photon detector, which would be of interest for quantum information and metrology applications. We consider two types of two-photon processes that can be observed using a very faint, but quantum-correlated biphoton field. These are optical… (More)