Andrew Fraine

Precise evaluation of polarization mode dispersion by separation of even- and odd-order effects in quantum interferometry

The use of quantum correlations between photons to separate measure even- and odd-order components of polarization mode dispersion (PMD) and chromatic dispersion in discrete optical elements is investigated. Two types of apparatus are discussed which use coincidence counting of entangled photon pairs to allow sub-femtosecond resolution for measurement of both PMD and chromatic dispersion. Group delays can be measured with a resolution of order 0.1 fs, whereas attosecond resolution can be achieved for phase delays.

Broadband source of polarization entangled photons.

A broadband source of polarization entangled photons based on type-II spontaneous parametric down conversion from a chirped PPKTP crystal is presented. With numerical simulation and experimental evaluation, we report a source of broadband polarization entangled states with a bandwidth of approximately 125 nm for use in quantum interferometry. The technique has the potential to become a basis for the development of flexible broadband sources with designed spectral properties.

Evaluation of polarization mode dispersion in a telecommunication wavelength selective switch using quantum interferometry

A polarization mode dispersion (PMD) measurement of a commercial telecommunication wavelength selective switch (WSS) using a quantum interferometric technique with polarization-entangled states is presented. Polarization-entangled photons with a broad spectral width covering the telecom band are produced using a chirped periodically poled nonlinear crystal. The first demonstration of a quantum metrology application using an industrial commercial device shows a promising future for practical high-resolution quantum interference.

The measurement and generation of orbital angular momentum using an optical geometric transformation

Previously we have demonstrated that the orbital angular momentum (OAM) of the light beam may be measured by image transformation that maps the azimuthal to linear transverse co-ordinate (Berkhout et al 2010 Phys. Rev. Lett. 105 153601). For each input OAM state the transmitted light is focused to a different transverse position enabling simultaneous measurement over many states. We present a significant improvement to our earlier design, extending the measurement bandwidth to greater than 50 OAM states and showing simultaneous measurement of the radial co-ordinate. We further demonstrate the transformation working in reverse, potentially allowing for the rapid switching of OAM modes.

Object Identification Using Correlated Orbital Angular Momentum (OAM) States

We present a novel approach that allows object identification using fewer resources than in conventional pixel-by-pixel imaging by exploiting the enhanced sensitivity of correlated orbital angular momentum states to multiple azimuthal Fourier coefficients.

High Resolution Optical Time-Domain Reflectometry using Superconducting Single-Photon Detectors

We discuss the advantages and limitations of single-photon optical time-domain reflectometry with superconducting single-photon detectors. The higher two-point resolution can be achieved due to superior timing performance of SSPDs in comparison with InGaAs APDs.

High Information Capacity Image Recognition Using Correlated Orbital Angular Momentum (OAM) States

We present a novel approach that allows object identification using fewer resources than in conventional pixel-by-pixel imaging by exploiting the enhanced sensitivity of correlated orbital angular momentum states to multiple azimuthal Fourier coefficients.

Orbital Angular Momentum Joint Spectrum Analysis for Efficient Object Recognition

Object recognition exploiting the two-dimensional orbital angular momentum joint spectrum using pairs of correlated photons is presented. The detection of rotational symmetries demonstrates a sparse sensing technique relevant to remote sensing and biological applications.

High Resolution Measurement of Polarization Mode Dispersion in Discrete Telecom Devices using Quantum Interferometry

A quantum interferometric technique for measuring polarization mode dispersion (PMD) of commercial telecommunication wavelength selective switch (WSS) demonstrates advantages of quantum optical technology over conventional measurement.

High Resolution Measurement of Polarization Mode Dispersion with Quantum Interferometry

A new quantum interferometric technique for measuring polarization mode dispersion with a higher precision than classical techniques is introduced. This approach simultaneously allows extracting chromatic and polarization mode dispersion parameters from a single optical setup.