ORCID Profile
0000-0001-8671-5987
Current Organisation
University of Southampton
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Publisher: Springer Science and Business Media LLC
Date: 15-01-2013
DOI: 10.1038/NCOMMS2349
Abstract: Increasing the complexity of quantum photonic devices is essential for many optical information processing applications to reach a regime beyond what can be classically simulated, and integrated photonics has emerged as a leading platform for achieving this. Here we demonstrate three-photon quantum operation of an integrated device containing three coupled interferometers, eight spatial modes and many classical and nonclassical interferences. This represents a critical advance over previous complexities and the first on-chip nonclassical interference with more than two photonic inputs. We introduce a new scheme to verify quantum behaviour, using classically characterised device elements and hierarchies of photon correlation functions. We accurately predict the device's quantum behaviour and show operation inconsistent with both classical and bi-separable quantum models. Such methods for verifying multiphoton quantum behaviour are vital for achieving increased circuit complexity. Our experiment paves the way for the next generation of integrated photonic quantum simulation and computing devices.
Publisher: Optica Publishing Group
Date: 02-07-2020
DOI: 10.1364/OE.389211
Abstract: A blazed chirped Bragg grating in a planar silica waveguide device was used to create an integrated diffractive element for a spectrometer. The grating diffracts light from a waveguide and creates a wavelength dependent focus in a manner similar to a bulk diffraction grating spectrometer. An external imaging system is used to analyse the light, later device iterations plan to integrate detectors to make a fully integrated spectrometer. Devices were fabricated with grating period chirp rates in excess of 100 nm mm −1 , achieving a focal length of 5.5 mm. Correction of coma aberrations resulted in a device with a footprint of 20 mm×10 mm, a peak FWHM resolution of 1.8 nm, a typical FWHM resolution of 2.6 nm and operating with a 160 nm bandwidth centered at 1550 nm.
Publisher: Springer Science and Business Media LLC
Date: 14-09-2014
Publisher: The Optical Society
Date: 06-09-2018
DOI: 10.1364/OE.26.024678
Publisher: Optica Publishing Group
Date: 29-03-2022
DOI: 10.1364/OE.445876
Abstract: We demonstrate that the stimulated Brillouin scattering of a 250 mm long distributed feedback Raman fiber laser can self-pulse with repetition rates up to 7 MHz, pulse widths of 25 ns, and peak powers of 1.2 W. While both CW and pulsed lasing are produced from a bespoke grating at 1119 nm this laser design could be constructed at almost any wavelength, as the Raman and Brillouin gain regions are relative to the pump wavelength. The laser has a low lasing threshold for a Raman laser of 0.55 W, a peak slope efficiency of 14 %, and a maximum average output of 0.25 W. An investigation of beating between pure Raman and Raman-pumped Brillouin lasing shows that the outputs of the two processes are highly correlated and thus the Brillouin lasing is essentially single-frequency when CW and near transform limited for pulsed operation. A phenomenological model of the Raman-Brillouin interaction shows that the pulsing behaviour of such a cavity is expected and produces very similar pulsing to that the seen in experimental results.
Publisher: Optica Publishing Group
Date: 02-07-2020
DOI: 10.1364/OE.396798
Abstract: We have demonstrated the inscription of Bragg gratings into five in idual cores of a seven core fiber using small spot direct UV writing. With this technique, we defined spectrally multiplexed Bragg gratings consecutively in separate cores as well as spectrally multiplexed gratings at the same longitudinal location in different cores. The effect of bending on the optical spectrum was evaluated to allow the differentiation between cross-exposure and cross-talk, and an alignment process to reduce cross-exposure by 13 dB was found.
Publisher: The Optical Society
Date: 31-10-2017
DOI: 10.1364/OE.25.028236
Publisher: The Optical Society
Date: 31-08-2018
Publisher: Optica Publishing Group
Date: 2004
Abstract: We report cross-section measurement and propagation measurement of modes of large mode area holey fibers using near-field scanning optical microscopy (NSOM). Mode profiles are measured at the fiber end face using a scanning optical fiber tip held 10 nm from the surface, and compared to theoretical models. Both litude and phase of the electric field of the propagating light is measured using NSOM techniques as a function of distance from the fiber end, from 10 nm to 150 microm. Good agreement is found between the data and simple scalar paraxial beam propagation simulations of theoretical mode profiles.
Publisher: The Optical Society
Date: 31-01-2019
DOI: 10.1364/OL.44.000703
Publisher: The Optical Society
Date: 08-04-2019
DOI: 10.1364/OE.27.011174
Publisher: American Association for the Advancement of Science (AAAS)
Date: 20-12-2012
Abstract: Although universal quantum computers ideally solve problems such as factoring integers exponentially more efficiently than classical machines, the formidable challenges in building such devices motivate the demonstration of simpler, problem-specific algorithms that still promise a quantum speedup. We constructed a quantum boson-s ling machine (QBSM) to s le the output distribution resulting from the nonclassical interference of photons in an integrated photonic circuit, a problem thought to be exponentially hard to solve classically. Unlike universal quantum computation, boson s ling merely requires indistinguishable photons, linear state evolution, and detectors. We benchmarked our QBSM with three and four photons and analyzed sources of s ling inaccuracy. Scaling up to larger devices could offer the first definitive quantum-enhanced computation.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for James Gates.