skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Derivation of the density matrix of a single photon produced in parametric down-conversion

Abstract

We discuss an effective numerical method of density matrix determination of fiber coupled single photon generated in process of spontaneous parametric down conversion in type I noncollinear configuration. The presented theory has been successfully applied in case of source utilized to demonstrate the experimental characterization of spectral state of single photon, what was reported in Wasilewski, Kolenderski, and Frankowski [Phys. Rev. Lett. 99, 123601 (2007)].

Authors:
 [1];  [2];  [3]
  1. Institute of Physics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland)
  2. Institute of Experimental Physics, Warsaw University, Hoza 69, 00-681 Warsaw (Poland)
  3. (QUANTOP), Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark)
Publication Date:
OSTI Identifier:
21313368
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 80; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevA.80.015801; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CONFIGURATION; CONVERSION; DENSITY MATRIX; FIBERS; OPTICS; PHOTONS; WAVELENGTHS

Citation Formats

Kolenderski, Piotr, Wasilewski, Wojciech, and Danish Research Foundation Center for Quantum Optics. Derivation of the density matrix of a single photon produced in parametric down-conversion. United States: N. p., 2009. Web. doi:10.1103/PHYSREVA.80.015801.
Kolenderski, Piotr, Wasilewski, Wojciech, & Danish Research Foundation Center for Quantum Optics. Derivation of the density matrix of a single photon produced in parametric down-conversion. United States. doi:10.1103/PHYSREVA.80.015801.
Kolenderski, Piotr, Wasilewski, Wojciech, and Danish Research Foundation Center for Quantum Optics. 2009. "Derivation of the density matrix of a single photon produced in parametric down-conversion". United States. doi:10.1103/PHYSREVA.80.015801.
@article{osti_21313368,
title = {Derivation of the density matrix of a single photon produced in parametric down-conversion},
author = {Kolenderski, Piotr and Wasilewski, Wojciech and Danish Research Foundation Center for Quantum Optics},
abstractNote = {We discuss an effective numerical method of density matrix determination of fiber coupled single photon generated in process of spontaneous parametric down conversion in type I noncollinear configuration. The presented theory has been successfully applied in case of source utilized to demonstrate the experimental characterization of spectral state of single photon, what was reported in Wasilewski, Kolenderski, and Frankowski [Phys. Rev. Lett. 99, 123601 (2007)].},
doi = {10.1103/PHYSREVA.80.015801},
journal = {Physical Review. A},
number = 1,
volume = 80,
place = {United States},
year = 2009,
month = 7
}
  • Two-photon interferometric quantum photon lithography for light of wavelength {lambda} is capable of beating the Rayleigh diffraction limit of resolution {lambda}/4 to the level of {lambda}/8. The required twin single-photon states |1>{sub a}|1>{sub b}, which are converted into maximally entangled states by a 50:50 beam splitter, can be generated from a nondegenerate parametric amplifier initially in vacuum states and with a weak pump field. Increasing the pump strength can slightly increase the production rate of the desired state and it will also increase the production of the twin two-photon states |2>{sub a}|2>{sub b}, which leads to an unwanted background term.more » In this paper we show that, assuming a weak pair coherent state as input to the amplifier, quantum interference can be used to quench the production of the |2>{sub a}|2>{sub b} state and to enhance the production of the |1>{sub a}|1>{sub b} state by almost sixfold.« less
  • We report the observation of spatial biphoton correlation in spontaneous parametric down conversion. The optical bench includes a type-I BBO crystal of effective length 2 mm, pumped by a 100 mW violet laser diode centered at 405.38 nm. Photon pairs are created with degenerate wavelength {approx_equal}810.76 nm. Once the horizontal counting rates have been measured, a simple geometrical recipe is shown to be useful in calculating bounds for the width of vertical counting rates. The spatial correlation between idler and signal photons is illustrated with a coincidence distribution of the coordinate pair (x{sub s},x{sub i}), with x{sub i,s} the idlermore » (signal) detector position in horizontal scan.« less
  • We propose an optical parametric down-conversion (PDC) scheme that does not suffer a trade-off between the state purity of single-photon wave packets and the rate of packet production. This is accomplished by modifying the PDC process by using a microcavity to engineer the density of states of the optical field at the PDC frequencies. The high-finesse cavity mode occupies a spectral interval much narrower than the bandwidth of the pulsed pump laser field, suppressing the spectral correlation, or entanglement, between signal and idler photons. Spectral filtering of the field occurs prior to photon creation rather than afterward as in mostmore » other schemes. Operator-Maxwell equations are solved to find the Schmidt-mode decomposition of the two-photon states produced. Greater than 99% pure-state packet production is predicted to be achievable.« less
  • Invariant entangled states remain unchanged under simultaneous identical unitary transformations of all their subsystems. We experimentally generate and characterize such invariant two-, four-, and six-photon polarization entangled states. This is done only with a suitable filtering procedure of multiple emissions of entangled photon pairs from a single source without any interferometric overlaps. We get the desired states utilizing bosonic emission enhancement due to indistinguishability. The setup is very stable and gives high interference contrasts. Thus, the process is a very likely candidate for various photonic demonstrations of quantum information protocols.
  • We present a full triple-coincidence analysis of photon-pair states generated by spontaneous parametric down-conversion. By increasing the coherence time of the source with the help of an intracavity setup, our measurements are not spoiled by detection time jitter. Signal-idler, but also thermal signal-signal, correlations are clearly resolved in this regime. Via introduction of an artificial coincidence window, we discuss in detail the transition to the previously studied cases where typically no single-arm correlation is observed. We investigate the heralded antibunching characteristics to show that in our system further studies of continuously generated photon states, possibly higher-photon-number entangled states, can bemore » performed with respect to their (non)applicability in quantum information tasks.« less