MPhys PhD

Lecturer

Telephone
+44 (0)131 451 8033
Email
p.a.dalgarno@hw.ac.uk
Address
Room 1.11
David Brewster Building
Heriot-Watt University
Paul Dalgarno
Research

Our research is based on developing pioneering optical and photonic techniques in order to address fundamental problems in biology and molecular science, pushing the boundaries of confocal and TIRF microscopy, single molecule spectroscopy, FRET and TCSPC. Example applications include real time 3D cellular imaging and probing RNA and DNA folding dynamics at the single molecule limit.

Real time 3D imaging and signal processing for live cell imaging

This STFC funded project utilizes novel imaging techniques for real time 3D particle tracking within living cells, and is in collaboration with Professor Alan Greenaway, Professor Rory Duncan and Dr Colin Rickman.

Traditional microscopes are ideal at imaging in only two dimensions, relying on physical scanning to capture three dimensional information. However, this is inherently slow and provides a severe limitation for studying living cells. The research adapts imaging technologies, originally designed for astronomy applications, to deliver a simple, user friendly, optical system for real time three dimensional imaging. A driving goal is to track single secretory vesicles within an entire living cell in all 3 spatial dimensions with super resolution accuracy (<20 nm in x-y, <50 nm in z).

Advanced photonics for biology

Photonics has revolutionized the way we observe the biological world, allowing for a real time, sterile probe of biological behavior in the sub-micron scale. However, the diffraction limit and the inherent low-photon flux of biological specimens create formidable challenges for acquiring, analyzing and interpreting biologically relevant data, particularly in-vivo. This project sets-out to break these barriers by developing and applying cutting edge physics techniques to investigate directly the functional biological world, such as bio-polymer dynamics, protein aggregation and vesicle function. The core methodology will focus on multi-parameter optical characterization combined with single molecule spectroscopy, FRET, FLIM, photonic enhancement and photonic manipulation.

Selected publications
  1. J. Prechtel, P.A. Dalgarno, R.H. Hadfield, J. McFarlane, A. Badolato, P.M. Petroff, and R.J. Warburton, "Fast electro-optics of a single quantum dot in a charge tunable device ". Journal of Applied Physics, 111, 043112, 2012.
  2. C. Kloeffel, P.A. Dalgarno, B. Urbaszek, B.D. Gerardot, D. Brunner, P.M. Petroff, D. Loss, and R.J. Warburton, "Controlling the Interaction of Electron and Nuclear Spins in a Tunnel-Coupled Quantum Dot". Physical Review Letters, 106, 46802 (2011).
  3. H.I.C. Dalgarno, P.A. Dalgarno, A.C. Dada, C.E. Towers, G.J. Gibson, R.M. Parton, I. Davis, R.J. Warburton, and A.H. Greenaway, "Nanometric depth resolution from multi-focal images in microscopy". Journal of the Royal Society Interface, 8, 942 (2011).
  4. C.M. Simon, T. Belhadj, B. Chatel, T. Amand, P. Renucci, A. Lemaitre, O. Krebs, P.A. Dalgarno, R.J. Warburton, X. Marie, and B. Urbaszek, "Robust Quantum Dot Exciton Generation via Adiabatic Passage with Frequency-Swept Optical Pulses". Physical Review Letters, 106, 166801 (2011).
  5. P.A. Dalgarno, H.I.C. Dalgarno, A. Putoud, R. Lambert, L. Paterson, D.C. Logan, D.P. Towers, R.J. Warburton, and A.H. Greenaway, "Multiplane imaging and three dimensional nanoscale particle tracking in biological microscopy". Optics Express, 18, 877 92010).
  6. D. Brunner, B.D. Gerardot, P.A. Dalgarno, G. Wust, K. Karrai, N.G. Stoltz, P.M. Petroff, and R.J. Warburton, "A Coherent Single-Hole Spin in a Semiconductor". Science, 325, 70 (2009).
  7. P.A. Dalgarno, J.M. Smith, J. McFarlane, B.D. Gerardot, K. Karrai, A. Badolato, P.M. Petroff, and R.J. Warburton, "Coulomb interactions in single charged self-assembled quantum dots: Radiative lifetime and recombination energy". Physical Review B, 77, 245311 (2008).
  8. P.A. Dalgarno, J. McFarlane, D. Brunner, R.W. Lambert, B.D. Gerardot, R.J. Warburton, K. Karrai, A. Badolato, and P.M. Petroff, "Hole recapture limited single photon generation from a single n-type charge-tunable quantum dot". Applied Physics Letters, 92, 193103 (2008).
  9. B.D. Gerardot, D. Brunner, P.A. Dalgarno, P. Ohberg, S. Seidl, M. Kroner, K. Karrai, N.G. Stoltz, P.M. Petroff, and R.J. Warburton, "Optical pumping of a single hole spin in a quantum dot". Nature, 451, 441 (2008).
  10. P.A. Dalgarno, M. Ediger, B.D. Gerardot, J.M. Smith, S. Seidl, M. Kroner, K. Karrai, P.M. Petroff, A.O. Govorov, and R.J. Warburton, "Optically induced hybridization of a quantum dot state with a filled continuum". Physical Review Letters, 100, 176801 (2008).
Biography

Paul received an MPhys in Physics in 2001 and a PhD in nano-optics in 2005, both from Heriot-Watt University, specializing in time-resolved spectroscopy of single self-assembled semiconducting quantum dots. From 2005-2009 Pauls research covered quantum dot physics, microscopy for biophotonics, single photon generation and detection and GHz electronics, all at Heriot-Watt. In 2010 Paul joined the single molecule biophotonics group at the University of St Andrews where he developed new microscopy techniques for studying the dynamics and functional landscape of RNA, DNA, vesicles and proteins at the single molecule/vesicle limit.

In 2012 Paul joined the Life-Physical Sciences Interface Laboratory at Heriot-Watt to work on applying novel optical techniques and signal processing for 3D vesicle tracking in live-cells. From 2013 onwards Paul will take the role of Research Fellow, developing an independent research program within the life sciences framework focussed on applying photonic techniques to understand the biological world at the single molecule limit.