• 4407 Citations
  • 31 h-Index
1964 …2020

Research output per year

If you made any changes in Pure these will be visible here soon.

Personal profile


Emeritus Professor Brian Orr (BSc Hons I, Sydney, 1964; MSc, Sydney, 1965; PhD, Bristol, UK, 1968; FRACI, FAIP, FOSA) is based in Macquarie University’s Department of Physics and Astronomy. He had previously held an 18-year academic appointment at the University of NSW before moving to Macquarie University as Professor of Chemistry (1988–2002). His administrative roles there included service as Head of School/Department (1989–92/1999–2002), as Deputy Chair of the Academic Senate (1989–92), and as a member of the University Council (1999–2002). He is Founding Director (2007–2010) of MQ Photonics – a University Research Centre incorporating the former Centre for Lasers and Applications, of which he was Deputy Director (1988–2002) and then Director (2003–07).

Brian's research covers experimental and theoretical topics in molecular and optical physics, most of them applying lasers and spectroscopy – notably energy-transfer processes, molecular spectra, photochemistry, chemical analysis, nonlinear optics, cavity-enhancement, photonic techniques, and laser-based instrumentation. He has long been involved in several professional chemical, optical and physical societies and has been active in journal editing (Optics Express, JOSAB, and Chemical Physics Letters). He was the first recipient (in 1994) of the Royal Australian Chemical Institute's Physical Chemistry Division Medal and (in 2005) the Australian Optical Society's W. H. (Beattie) Steel Medal. In 2004, The Optical Society (OSA) awarded him its prestigious William F. Meggers Award “for outstanding work in spectroscopy.”

According to Google Scholar (14 June 2018), Brian Orr’s whole-of-career publications performance is: h-index = 35; i10-index = 110; total citations = 5864.

Brian’s recent major research publications are as follows:
• B.J.Orr, “Collision-induced rovibrational energy transfer in small polyatomic molecules: the role of intramolecular perturbations,” accepted on 12 June 2018 for publication in Molecular Physics (35 journal pages, including 228 refs, 7 figs & 23 equations); DOI 10.1080/00268976.2018.1490463 (2018).
This recently accepted MS covers experiments and mechanisms concerning the role of intramolecular perturbations in enhancing (or suppressing) the efficiency of rotationally resolved V–V transfer in rovibrational manifolds of small polyatomic molecules, such as CO2, D2CO and C2H2.
• Y.He, B.J.Orr, K.G.H.Baldwin, R.B.Warrington, M.J.Wouters, A.N.Luiten, P.Mirtschin, T.Tzioumis, C.Phillips, J.Stevens, B.Lennon, S.Munting, G.Aben, T.Newlands and T.Rayner, “Long-distance telecom-fiber transfer of a radio-frequency reference for radio astronomy,” Optica 5, 138–146 (2018).
A major ARC-funded consortium has devised cost-effective ways to transmit a highly stable frequency reference shared by widely separated radio telescopes, enabling the signals from the facilities to be aligned in time and combined coherently as is necessary for very-long-baseline interferometry (VLBI).
• B.J.Orr, J.G.Haub, Y.He and R.T.White, “Spectroscopic applications of tunable optical parametric oscillators,” in Tunable Laser Applications, 3rd edn., ed. F.J.Duarte (CRC Press, New York, 2016), Ch. 2, pp. 17–142 (incl. 666 references; ISBN 97811482261066); this is a substantial update of corresponding chapters in 1st & 2nd editions (1995 & 2009).
A comprehensive review of the nonlinear-optical theory, instrumental design and frequency-control strategies for tunable optical parametric oscillators (OPOs), with emphasis on their spectroscopic applications.
• M.Kono, Y.He, K.G.H.Baldwin and B.J.Orr, “Sub-Doppler two-photon-excitation Rydberg spectroscopy of atomic xenon: mass-selective studies of isotopic and hyperfine structure,” J. Phys. B 49, 065002/1–065002/15 (2016).
The latest paper in a series that uses a high-performance nonlinear-optical ultraviolet light source for ionisation-detected studies of high-resolution sub-Doppler atomic spectra.
• Y.He, C.Jin, R.Kan, J.Liu, W.Liu, J.Hill, I.M.Jamie and B.J.Orr, “Remote open-path cavity-ringdown spectroscopic sensing of trace gases in air, based on distributed passive sensors linked by km-long optical fibers,” Optics Express 22, 13170–13189 (2014).
The latest paper in a series using rapidly swept cavity-ringdown spectroscopy for optical-fibre-coupled measurements of gas-phase molecules in industrial, biomedical, agricultural and environmental situations.
• B.J.Orr and Y.He, “Cavity-based absorption spectroscopy techniques,” in Laser Spectroscopy for Sensing: Fundamentals, Techniques and Applications, ed. M.Baudelet (Woodhead Publishing, Cambridge, UK, 2014), Woodhead Publishing Series in Electronic and Optical Materials, Number 43, Part II, Laser Spectroscopy Techniques, Chap. 6, pp. 167–207; ISBN 978-0-85709-273-1; a substantial update will soon appear in a 2nd edition.
A resonant optical cavity can greatly enhance absorption-spectroscopic sensitivity relative to cavity-free measurements.

Fingerprint Dive into the research topics where Brian Orr is active. These topic labels come from the works of this person. Together they form a unique fingerprint.

  • 2 Similar Profiles

Network Recent external collaboration on country level. Dive into details by clicking on the dots.


MQ Photonics Research Centre

Coutts, D. W., Withford, M., Orr, B., Carman, R., Connally, R., Dawes, J., Browne, P., Downes, J., Fuerbach, A., Goldys, E., Dekker, P., He, Y., Jin, D., Kane, D., Marshall, G., Mildren, R., Pask, H., Piper, J., Rabeau, J., Spence, D., Drozdowicz-Tomsia, K., Town, G., Zvyagin, A. & Steel, M.

1/07/07 → …

Project: Research

Creating a National Time and Frequency Network for Australia

Orr, B., Luiten, A. N., Baldwin, K., Hartnett, J., Tingay, S., Dickey, J., Quinn, P., Lawrence, J., Light, P., Warrington, R., Aben, G., Phillps, I., Tzioumis, A., Santarelli, G., McClelland, D., Sharma, V. & Fisk, P.


Project: Research

Using high-resolution lasers to test quantum electrodynamics

Orr, B., Baldwin, K., Warrington, R. & Eyler, E.


Project: Research

Research Outputs

Two-photon excitation of two Rydberg levels of O2 above 95 130 cm–1: Rotational-state dependence of predissociation linewidths

Kono, M., He, Y., Lewis, B. R., Gibson, S. T., Baldwin, K. G. H. & Orr, B. J., 1 Mar 2020, In : Journal of Quantitative Spectroscopy and Radiative Transfer. 244, 10 p., 106841.

Research output: Contribution to journalArticle

  • Long-distance telecom-fiber transfer of a radio-frequency reference for radio astronomy

    He, Y., Baldwin, K. G. H., Orr, B. J., Warrington, R. B., Wouters, M. J., Luiten, A. N., Mirtschin, P., Tzioumis, T., Phillips, C., Stevens, J., Lennon, B., Munting, S., Aben, G., Newlands, T. & Rayner, T., 20 Feb 2018, In : Optica. 5, 2, p. 138-146 9 p.

    Research output: Contribution to journalArticle

  • 25 Citations (Scopus)

    Precision two-photon-excitation spectroscopy of atomic and molecular Rydberg states

    Baldwin, K. G. H., Kono, M., Orr, B. J. & He, Y., 1 Jan 2018, Fourier Transform Spectroscopy 2018. Washington, D. C.: OSA - The Optical Society, 2 p. JT2A.21

    Research output: Chapter in Book/Report/Conference proceedingConference proceeding contribution

  • Fiber-optical coupling in agricultural and environmental sensing, based on open-path cavity ringdown spectroscopy

    Orr, B. J., He, Y., Hill, J. & Jamie, I. M., 29 Aug 2016, Photonics and Fiber Technology 2016 (ACOFT, BGPP, NP): proceedings. OSA - The Optical Society, p. 1-2 2 p. AT3C.5

    Research output: Chapter in Book/Report/Conference proceedingConference proceeding contribution