Search results for " parametric"

Record Phase Sensitive Extinction Ratio in a Silicon Germanium Waveguide

2015

A binary step-like phase response and phase-sensitive extinction ratio in excess of 28dB under CW pump operation was demonstrated in a 20mm-long low birefringence SiGe waveguide, using a polarization-assisted phase sensitive amplifier scheme.

Demonstration of polarization pulling using a fiber-optic parametric amplifier

2012

International audience; We report the observation of all-optical polarization pulling of an initially polarization-scrambled signal using parametric amplification in a highly nonlinear optical fiber. Broadband polarization pulling has been achieved both for the signal and idler waves with up to 25 dB gain using the strong polarization sensitivity of parametric amplifiers. We further derive the probability distribution function for the final polarization state, assuming a randomly polarized initial state, and we show that it agrees well with the experiments.

Nonlinear Resonance Effects in Pattern Formation in Optical Parametric Oscillators

2005

Information systems for the conservation and fruition of cultura heritage. The church of Santa Trinità di Delia

2016

Lo studio descrive il processo di conoscenza avviato su uno degli esempi monumentali più rappresentativi dell’architettura normanna della prima metà del XII sec. in Sicilia: la chiesa della Trinità di Delia a Castelvetrano (TP). Le fasi del rilievo e della rappresentazione 3D degli elementi costruttivi e decorativi seguono un approccio parametrico costituendo un sistema informativo implementabile di supporto per successivi interventi di restauro conservativo della struttura. Il workflow è struturato in modo tale da impiegare tecnologie hardware / software low-cost, descrivendo metodiche procedurali di elaborazione dati trasferibili all’attività professionale. The study describes the knowled…

Synchronization of optical photons for quantum information processing

2015

We observe the Hong-Ou-Mandel interference via homodyne tomography on two photons extracted from two quantum memories.

Comprehensive formulation of the temperature dependent dispersion of optical materials; illustration with the case of temperature tuning of a mid-IR …

2009

International audience; The temperature dependence of refractive indices of optical materials is characterized in this work by what we call their normalized thermo-optic coefficients. These ones are determined experimentally through interferometric measurements of thermal expansion, and changes in optical thickness at a few laser wavelengths as function of temperature. A suitable vectorial formalism applied to these data allows predicting the thermal evolution of the refractive index all over the useful range of transparency. The validity and reliability of our methodology is demonstrated through temperature tuning of a mid-IR HgGa2S4 OPO, pumped at 1.0642 μm by a Nd:YAG laser. Measured the…

Acoustic transmitters for underwater neutrino telescopes.

2012

In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing recei…

Creating highly squeezed vacua in hybrid Laguerre-Gauss modes

2009

In this communication we study the above threshold quantum properties of a degenerate optical parametric oscillator (DOPO) tuned to a given transverse mode family at the signal frequency. We will show that under this configuration DOPOs are versatile sources of nonclassical light, in which one could be able to generate highly squeezed vacua with the non trivial shapes of Hybrid Laguerre-Gauss modes.

Entanglement swapping in a Franson interferometer setup

2007

We propose a simple scheme to swap the non local correlations, characteristic of a Franson interferometric setup, between pairs of frequency entangled photons emitted by distinct non linear crystals in a parametric down conversion process. Our scheme consists of two distinct sources of frequency entangled photons. One photon of each pair is sent to a separate Mach - Zender interferometer while the other photons of the pairs are mixed by a beam splitter and then detected in a Ou - Mandel interferometer. For suitably postselected joint measuremetns, the photons sent at the Mach -Zender show a coincidence photocount statistics which depends non locally on the settings of the two interferometer…

The electron affinity of phosphorus

2007

We have measured the energies of all three fine structure components in the 3PJ ground state of the negative ion of phosphorus using laser photodetachment threshold spectroscopy. The experiment yielded an electron affinity of 746.68(6) meV. The ΔJ = 2–0, 2–1 and 1–0 fine structure splittings were determined to be 32.73(7) meV, 22.48(7) meV and 10.25(3) meV, respectively. In the experiment, a mass selected beam of P− ions was merged with the output from a pulsed infrared optical parametric oscillator. The residual atoms produced in the photodetachment process were detected and used as a monitor of the photon-energy dependence of the relative cross section. The Wigner law was fitted to each o…