31 research outputs found
Experimental realization of a measurement conditional unitary operation at single photon level and application to detector characterization
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 the polarization of a photon produced by means of Type-II
Parametric Down Conversion conditional to a polarization measurement on the
correlated photon. We then propose a new scheme for measuring the quantum
efficiency of a single photon detection apparatus by using this set-up. We
present experimental results obtained with this scheme compared with {\it
traditional} biphoton calibration. Our results show the interesting
potentiality of the suggested scheme.Comment: to appear in Proc. of SPIE meeting, Denver august 200
Absolute Quantum Efficiency Measurements by Means of Conditioned Polarization Rotation
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 selection. We present
experimental results obtained with this scheme
Mise en pratique for the definition of the candela and associated derived units for photometric and radiometric quantities in the International System of Units (SI)
open8The purpose of this mise en pratique, prepared by the Consultative Committee for Photometry
and Radiometry (CCPR) of the International Committee for Weights and Measures (CIPM)
and formally adopted by the CIPM, is to provide guidance on how the candela and related
units used in photometry and radiometry can be realized in practice. The scope of the mise
en pratique recognizes the fact that the two fields of photometry and radiometry and their
units are closely related through the current definition of the SI base unit for the photometric
quantity, luminous intensity: the candela.
The previous version of the mise en pratique was applied only to the candela whereas
this updated version covers the realization of the candela and other related units used for
photometric and radiometric quantities. Recent advances in the generation and manipulation
of individual photons show great promise of producing radiant fluxes with a well-established
number of photons. Thus, this mise en pratique also includes information on the practical
realization of units for photometric and radiometric quantities using photon-number-based
techniques. In the following, for units used for photometric and radiometric quantities, the
shorter term, photometric and radiometric units, is generally used.
Section 1 describes the definition of the candela which introduces a close relationship
between photometric and radiometric units. Sections 2 and 3 describe the practical realization
of radiometric and photon-number-based units, respectively. Section 4.1 explains how, in
general, photometric units are derived from radiometric units. Sections 4.2–4.5 deal with the
particular geometric conditions for the specific photometric units. Section 5 deals very briefly
with the topic of determination of measurement uncertainties in photometry.openZwinkels, Joanne; Sperling, Armin; Goodman, Teresa; Acosta, Joaquin Campos; Ohno, Yoshi; Rastello, Maria Luisa; Stock, Michael; Woolliams, EmmaZwinkels, Joanne; Sperling, Armin; Goodman, Teresa; Acosta, Joaquin Campos; Ohno, Yoshi; Rastello, Maria Luisa; Stock, Michael; Woolliams, Emm
Mise en pratique for the definition of the candela and associated derived units for photometric and radiometric quantities in the International System of Units (SI)
The purpose of this mise en pratique, prepared by the Consultative Committee for Photometry and Radiometry (CCPR) of the International Committee for Weights and Measures (CIPM) and formally adopted by the CIPM, is to provide guidance on how the candela and related units used in photometry and radiometry can be realized in practice. The scope of the mise en pratique recognizes the fact that the two fields of photometry and radiometry and their units are closely related through the current definition of the SI base unit for the photometric quantity, luminous intensity: the candela.
The previous version of the mise en pratique was applied only to the candela whereas this updated version covers the realization of the candela and other related units used for photometric and radiometric quantities. Recent advances in the generation and manipulation of individual photons show great promise of producing radiant fluxes with a well-established number of photons. Thus, this mise en pratique also includes information on the practical realization of units for photometric and radiometric quantities using photon-number-based techniques. In the following, for units used for photometric and radiometric quantities, the shorter term, photometric and radiometric units, is generally used.
Section 1 describes the definition of the candela which introduces a close relationship between photometric and radiometric units. Sections 2 and 3 describe the practical realization of radiometric and photon-number-based units, respectively. Section 4.1 explains how, in general, photometric units are derived from radiometric units. Sections 4.2\u20134.5 deal with the particular geometric conditions for the specific photometric units. Section 5 deals very briefly with the topic of determination of measurement uncertainties in photometry.Peer reviewed: YesNRC publication: Ye
Detection of multimode spatial correlation in PDC and application to the absolute calibration of a CCD camera
We propose and demonstrate experimentally a new method based on the spatial
entanglement for the absolute calibration of analog detector. The idea consists
on measuring the sub-shot-noise intensity correlation between two branches of
parametric down conversion, containing many pairwise correlated spatial modes.
We calibrate a scientific CCD camera and a preliminary evaluation of the
statistical uncertainty indicates the metrological interest of the method
Predictable quantum efficient detector based on n-type silicon photodiodes
The predictable quantum efficient detector (PQED) consists of two custom-made induced junction photodiodes that are mounted in a wedged trap configuration for the reduction of reflectance losses. Until now, all manufactured PQED photodiodes have been based on a structure where a SiO2 layer is thermally grown on top of p-type silicon substrate. In this paper, we present the design, manufacturing, modelling and characterization of a new type of PQED, where the photodiodes have an Al2O3 layer on top of n-type silicon substrate. Atomic layer deposition is used to deposit the layer to the desired thickness. Two sets of photodiodes with varying oxide thicknesses and substrate doping concentrations were fabricated. In order to predict recombination losses of charge carriers, a 3D model of the photodiode was built into Cogenda Genius semiconductor simulation software. It is important to note that a novel experimental method was developed to obtain values for the 3D model parameters. This makes the prediction of the PQED responsivity a completely autonomous process. Detectors were characterized for temperature dependence of dark current, spatial uniformity of responsivity, reflectance, linearity and absolute responsivity at the wavelengths of 488 nm and 532 nm. For both sets of photodiodes, the modelled and measured responsivities were generally in agreement within the measurement and modelling uncertainties of around 100 parts per million (ppm). There is, however, an indication that the modelled internal quantum deficiency may be underestimated by a similar amount. Moreover, the responsivities of the detectors were spatially uniform within 30 ppm peak-to-peak variation. The results obtained in this research indicate that the n-type induced junction photodiode is a very promising alternative to the existing p-type detectors, and thus give additional credibility to the concept of modelled quantum detector serving as a primary standard. Furthermore, the manufacturing of PQEDs is no longer dependent on the availability of a certain type of very lightly doped p-type silicon wafers.Peer reviewe