Professor Timothy Ralph
Professor

Timothy Ralph

Email: 
Phone: 
+61 7 334 69693

Background

Professor Ralph obtained a BSc Hons from Macquarie University in 1989 and a PhD in Physics from The Australian National University in 1993. He has held three Australian Research Council Fellowships - Postdoctoral, QEII and Professorial. He is currently Node Director for the ARC Centre of Excellence for Quantum Computation and Communication Technology at the University of Queensland.

Availability

Professor Timothy Ralph is:
Available for supervision
Media expert

Fields of research

Physical Sciences

Qualifications

  • Bachelor (Honours) of Science (Advanced), Macquarie University
  • Doctor of Philosophy, Australian National University

Research interests

  • Linear Optics Quantum Computation.

    As part of the Centre for Quantum Computation and Communication Technology we are attempting to understand and implement simple quantum gates using the techniques of linear optics and measurement induced state projection.

  • Quantum Communication with Lasers.

    Quantum information techniques allow one to communicate with absolute security, amongst other applications. As part of the Centre for Quantum Computation and Communication Technology we are developing such secure communication protocols based on sending coherent states of light and measuring their amplitudes.

  • Relativistic Quantum Information.

    This project examines the interface between quantum mechanics, general relativity and information theory. It asks, both at a fundamental and practical level, what the ramifications for quantum information theory are when space-time curvature and rapid motion are introduced.

Search Professor Timothy Ralph’s works on UQ eSpace

429 works between 1991 and 2025
All (429) Journal Article (325) Book Chapter (7) Conference Publication (87) Book (2) Other Outputs (8)

401 - 420 of 429 works

1998

Journal Article

Squeezed light in a frontal-phase-modulated signal-recycled interferometer

Chickarmane, V, Dhurandhar, SV, Ralph, TC, Gray, M, Bachor, HA and McClelland, DE (1998). Squeezed light in a frontal-phase-modulated signal-recycled interferometer. Physical Review a, 57 (5), 3898-3912. doi: 10.1103/PhysRevA.57.3898

Squeezed light in a frontal-phase-modulated signal-recycled interferometer

1998

Journal Article

Noiseless independent signal and power amplification

Huntington, EH, Lam, PK, Ralph, TC, McClelland, DE and Bachor, HA (1998). Noiseless independent signal and power amplification. Optics Letters, 23 (7), 540-542. doi: 10.1364/OL.23.000540

Noiseless independent signal and power amplification

1998

Journal Article

Feedback control of laser intensity noise

Buchler, BC, Huntington, EH, Harb, CC and Ralph, TC (1998). Feedback control of laser intensity noise. Physical Review a, 57 (2), 1286-1294. doi: 10.1103/PhysRevA.57.1286

Feedback control of laser intensity noise

1998

Journal Article

Noiseless electro-optic processing of optical signals generated with squeezed light

Lam, PK, Ralph, TC, Huntington, EH, McClelland, DE and Bachor, HA (1998). Noiseless electro-optic processing of optical signals generated with squeezed light. Optics Express, 2 (3), 100-109. doi: 10.1364/OE.2.000100

Noiseless electro-optic processing of optical signals generated with squeezed light

1998

Journal Article

Feedback control of the intensity-noise of injection locked lasers

Huntington, EH, Buchler, BC, Harb, CC, Ralph, TC, McClelland, DE and Bachor, HA (1998). Feedback control of the intensity-noise of injection locked lasers. Optics Communications, 145 (1-6), 359-366. doi: 10.1016/S0030-4018(97)00419-7

Feedback control of the intensity-noise of injection locked lasers

1997

Journal Article

Intensity-noise dependence of Nd:YAG lasers on their diode-laser pump source

Harb, CC, Ralph, TC, Huntington, EH, McClelland, DE, Bachor, HA and Freitag, I (1997). Intensity-noise dependence of Nd:YAG lasers on their diode-laser pump source. Journal of the Optical Society of America B-Optical Physics, 14 (11), 2936-2945. doi: 10.1364/JOSAB.14.002936

Intensity-noise dependence of Nd:YAG lasers on their diode-laser pump source

1997

Journal Article

Robust transmission and reconstruction of fragile optical states

Ralph, TC (1997). Robust transmission and reconstruction of fragile optical states. Physical Review a, 56 (5), 4187-4192. doi: 10.1103/PhysRevA.56.4187

Robust transmission and reconstruction of fragile optical states

1997

Journal Article

Noiseless signal amplification using positive electro-optic feedforward

Lam, P. K., Ralph, T. C., Huntington, E. H. and Bachor, H. A. (1997). Noiseless signal amplification using positive electro-optic feedforward. Physical Review Letters, 79 (8), 1471-1474. doi: 10.1103/PhysRevLett.79.1471

Noiseless signal amplification using positive electro-optic feedforward

1997

Journal Article

Investigation of polarisation effects in injection locked lasers

Huntington, EH, Harb, CC, Ralph, TC, Bachor, HA and McClelland, DE (1997). Investigation of polarisation effects in injection locked lasers. Applied Physics B-Lasers and Optics, 64 (5), 507-514. doi: 10.1007/s003400050207

Investigation of polarisation effects in injection locked lasers

1997

Journal Article

Low noise amplification and efficient squeezing from rate matched lasers

Ralph, TC (1997). Low noise amplification and efficient squeezing from rate matched lasers. Physical Review a, 55 (3), 2326-2333. doi: 10.1103/PhysRevA.55.2326

Low noise amplification and efficient squeezing from rate matched lasers

1997

Journal Article

Noiseless amplification in cavity-based optical systems with an internal two-photon process .2. Self-frequency-doubling laser and second-harmonic generation, self-down-converting laser - Comment

White, AG, Ralph, TC and Bachor, HA (1997). Noiseless amplification in cavity-based optical systems with an internal two-photon process .2. Self-frequency-doubling laser and second-harmonic generation, self-down-converting laser - Comment. Journal of Modern Optics, 44 (3), 651-652. doi: 10.1080/09500349708232928

Noiseless amplification in cavity-based optical systems with an internal two-photon process .2. Self-frequency-doubling laser and second-harmonic generation, self-down-converting laser - Comment

1996

Journal Article

Intensity-noise properties of injection-locked lasers

Harb, CC, Ralph, TC, Huntington, EH, Freitag, I, McClelland, DE and Bachor, HA (1996). Intensity-noise properties of injection-locked lasers. Physical Review a, 54 (5), 4370-4382. doi: 10.1103/PhysRevA.54.4370

Intensity-noise properties of injection-locked lasers

1996

Journal Article

Intensity noise of injection-locked lasers: Quantum theory using a linearized input-output method

Ralph, TC, Harb, CC and Bachor, HA (1996). Intensity noise of injection-locked lasers: Quantum theory using a linearized input-output method. Physical Review a, 54 (5), 4359-4369. doi: 10.1103/PhysRevA.54.4359

Intensity noise of injection-locked lasers: Quantum theory using a linearized input-output method

1996

Journal Article

Experimental test of modular noise propagation theory for quantum optics

White, Andrew G., Taubman, Matthew S., Ralph, Timothy C., Lam, Ping Koy, McClelland, David E. and Bachor, Hans-A. (1996). Experimental test of modular noise propagation theory for quantum optics. Physical Review a, 54 (4), 3400-3404. doi: 10.1103/PhysRevA.54.3400

Experimental test of modular noise propagation theory for quantum optics

1996

Journal Article

Active versus passive squeezing by second-harmonic generation

White, AG, Ralph, TC and Bachor, HA (1996). Active versus passive squeezing by second-harmonic generation. Journal of the Optical Society of America B-Optical Physics, 13 (7), 1337-1346. doi: 10.1364/JOSAB.13.001337

Active versus passive squeezing by second-harmonic generation

1996

Conference Publication

Experiments and theory of laser noise: Consequences for squeezing and injection locking

Bachor, HA, Taubman, MS, Ralph, TC, Harb, CC, White, AG and McClelland, DE (1996). Experiments and theory of laser noise: Consequences for squeezing and injection locking. ICONO 95 Conference - Atomic and Quantum Optics: High-Precision Measurements, St Petersburg Russia, Jun 27-Jul 01, 1995. BELLINGHAM: SPIE - INT SOC OPTICAL ENGINEERING. doi: 10.1117/12.239824

Experiments and theory of laser noise: Consequences for squeezing and injection locking

1995

Journal Article

NOISELESS AMPLIFICATION OF THE COHERENT AMPLITUDE OF BRIGHT SQUEEZED-LIGHT USING A STANDARD LASER-AMPLIFIER (VOL 119, PG 301, 1995)

RALPH, TC and BACHOR, HA (1995). NOISELESS AMPLIFICATION OF THE COHERENT AMPLITUDE OF BRIGHT SQUEEZED-LIGHT USING A STANDARD LASER-AMPLIFIER (VOL 119, PG 301, 1995). Optics Communications, 122 (1-3), 94-98. doi: 10.1016/0030-4018(95)00625-0

NOISELESS AMPLIFICATION OF THE COHERENT AMPLITUDE OF BRIGHT SQUEEZED-LIGHT USING A STANDARD LASER-AMPLIFIER (VOL 119, PG 301, 1995)

1995

Journal Article

Numerical Modeling of Evanescent-Wave Atom Optics

Savage, CM, Gordon, D and Ralph, TC (1995). Numerical Modeling of Evanescent-Wave Atom Optics. Physical Review a, 52 (6), 4741-4746. doi: 10.1103/PhysRevA.52.4741

Numerical Modeling of Evanescent-Wave Atom Optics

1995

Journal Article

Noiseless Amplification of the Coherent Amplitude of Bright Squeezed-Light Using a Standard Laser-Amplifier

Ralph, TC and Bachor, HA (1995). Noiseless Amplification of the Coherent Amplitude of Bright Squeezed-Light Using a Standard Laser-Amplifier. Optics Communications, 119 (3-4), 301-304. doi: 10.1016/0030-4018(95)00336-7

Noiseless Amplification of the Coherent Amplitude of Bright Squeezed-Light Using a Standard Laser-Amplifier

1995

Conference Publication

Progress in the Search for the Optimum Light-Source - Squeezing Experiments with a Frequency Doubler

Bachor, HA, Ralph, TC, Taubman, MS, White, AG, Harb, CC and McClelland, DE (1995). Progress in the Search for the Optimum Light-Source - Squeezing Experiments with a Frequency Doubler. Workshop on Non-Classical Light/Satellite Meeting on Application of Techniques and Methods of Non-Classical Light - Gravitational Wave Detection, Quantum Cryptography and Quantum Computing, Corvara Italy, Jan 28-Feb 04, 1995. BRISTOL: IOP PUBLISHING LTD. doi: 10.1088/1355-5111/7/4/024

Progress in the Search for the Optimum Light-Source - Squeezing Experiments with a Frequency Doubler

Current funding

  • 2024 - 2027
    Deployable Quantum Relay (DSP Multi-Party Collaborative Project led by Griffith University)
    Commonwealth Defence Science and Technology Group
    Open grant
  • 2023 - 2025
    Quantum Communications with Continuous Variables (UNSW subcontract agreement)
    University of New South Wales
    Open grant
  • 2018 - 2025
    ARC Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) (ARC Centre of Excellence administered by UNSW)
    University of New South Wales
    Open grant

Past funding

  • 2021 - 2024
    A Space-Based Quantum Communications Platform using Continuous Variables (ARC Linkage Project led by University of NSW)
    University of New South Wales
    Open grant
  • 2019 - 2021
    Enabling quantum information technology with 60 photons and beyond
    United States Asian Office of Aerospace Research and Development
    Open grant
  • 2019 - 2020
    Platform independent studies on optimising quantum repeater architectures (Australian Department of Defence grant administered by QuintessenceLabs Pty Ltd)
    Quintessencelabs Pty Ltd
    Open grant
  • 2017 - 2020
    Quantum Key Distribution (QKD) System
    Quintessencelabs Pty Ltd
    Open grant
  • 2011 - 2018
    ARC Centre of Excellence for Quantum Computation and Communication Technology (ARC COE administered by the University of New South Wales)
    University of New South Wales
    Open grant
  • 2011 - 2013
    Quantum Optics and Quantum Information
    Vice-Chancellor's Senior Research Fellowship
    Open grant
  • 2010
    Quantum memory
    Australian National University
    Open grant
  • 2008 - 2012
    Quantum repeater technologies for continuous variable (ARC Discovery Project DP0879277 administered by ANU)
    Australian National University
    Open grant
  • 2006 - 2010
    Optical Quantum Computation
    ARC Discovery Projects
    Open grant
  • 2003 - 2010
    ARC Centre of Excellence for Quantum Computer Technology (UNSW lead institution)
    ARC Centres of Excellence
    Open grant
  • 2003 - 2005
    Quantum Photonics- Travel Award
    Australian National University
    Open grant
  • 2002 - 2004
    Towards Quantum Computation with Light
    UQ Foundation Research Excellence Awards - DVC(R) Funding
    Open grant
  • 2002 - 2004
    ARC Discovery Project - Quantum Photonics with continuous laser beams
    Australian National University
    Open grant
  • 2001 - 2004
    Experimental Implementation of Efficient Linear Optics Quantum Computation
    United States Army Research Office
    Open grant
  • 2000
    Optical entangler for Quantum Communication
    Australian National University
    Open grant
  • 2000 - 2005
    Quantum Information with Continuous Variables
    ARC Australian Research Fellowship/QEII F/ship
    Open grant
  • 2000
    Quantum information with continuous variables
    UQ New Staff Research Start-Up Fund
    Open grant

Availability

Professor Timothy Ralph is:
Available for supervision

Before you email them, read our advice on how to contact a supervisor.

Available projects

  • Optical Quantum Computation

    As part of the Centre for Quantum Computation and Communication Technology we are attempting to understand and implement optical quantum computation using the techniques of linear optic networks and measurement induced state projection. Projects are available examining intemediate scale protocols and algorithms as well as large scale architectures.

  • Quantum communication with lasers

    Quantum information techniques allow one to communicate with absolute security, amongst other applications. As part of the Centre for Quantum Computation and Communication Technology we are developing such secure communication protocols based on sending coherent and squeezed states of light and measuring their amplitudes. Projects concerning quantum repeaters for extending communication links and satellite to ground quantum communication are available.

  • Relativistic quantum information

    Projects are available that involve examining the interface between quantum mechanics, general relativity and information theory. They ask, both at a fundamental and practical level, what the ramifications for quantum information theory are when space-time curvature, rapid motion and/or very fast transformations are introduced.

Supervision history

Current supervision

  • Doctor Philosophy

    Production of quantum communication systems capable of operating onboard low-earth orbit satellites and developing integrated quantum and classical satellite communication protocols.

    Principal Advisor

  • Doctor Philosophy

    Practical applications of quantum sampling algorithms

    Principal Advisor

  • Master Philosophy

    Quantum effects in general relativistic spacetimes

    Principal Advisor

  • Doctor Philosophy

    Production of quantum communication systems capable of operating onboard low-earth orbit satellites and developing integrated quantum and classical satellite communication protocols.

    Principal Advisor

  • Master Philosophy

    Resolving paradoxes of closed timelike curves

    Principal Advisor

  • Doctor Philosophy

    Quantum mechanics near closed timelike curves

    Principal Advisor

  • Doctor Philosophy

    Beyond quantum field theory on a curved background

    Principal Advisor

  • Doctor Philosophy

    Demonstration of relativistic Bohmian trajectories of photons

    Associate Advisor

    Other advisors: Dr Daniel Peace, Associate Professor Jacqui Romero

  • Doctor Philosophy

    Thermodynamic fluctuation relations for gravitating quantum systems

    Associate Advisor

    Other advisors: Dr Carolyn Wood, Dr Laura Henderson

Completed supervision

Enquiries

Contact Professor Timothy Ralph directly for media enquiries about:

  • Laser noise - physics
  • Optics - quantum
  • Physics
  • Quantum information
  • Quantum key distribution with continuous variables
  • Quantum optics
  • Quantum physics
  • Teleportation

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