IN THIS SECTION
Integrated Photonic Devices
The Integrated Photonic Devices Group, led by Professor James Wilkinson, was established in early 1990 to meet the demand for optical device functions of increasing complexity and parallelism.
Planar photonic devices are exploited in applications as diverse as telecommunications, tuneable and short-pulse miniature laser light sources, diagnostics in medicine, the environment and food processing, and early-warning sensors for biological agents. We exploit surface science, waveguide engineering, laser physics and microstructure technology to realise robust mass-producible integrated optical circuits, to further the monolithic integration of diverse devices, and to develop novel materials processing for optoelectronic devices.
The group is currently active in the fields of microsphere resonator coupled planar lightwave circuits, optical sorting of micro- nano- and bio-particles, sapphire waveguide optics, optical biosensors, optofluidic integration for bioanalysis, waveguide lasers and amplifiers, nonlinear optics, and microstructured dielectric films and materials.
Key research breakthroughs:
- First monomode glass waveguide laser (1990) "Low-Threshold Monomode Ion-Exchanged Waveguide Lasers in Neodymium-Doped BK-7 Glass", E.K.Mwarania, L.Reekie, J.Wang, & J.S.Wilkinson; Electronics Letters, 26, pp.1317-8, 1990.
- Integrated optoelectrochemical sensor (1992) "Optoelectrochemical Thin-Film Chlorine Sensor Employing Evanescent Fields on Planar Optical Waveguides", C.Piraud, E.K.Mwarania, G.Wylangowski, K.O'Dwyer, D.J.Schiffrin, & J.S.Wilkinson, Analytical Chemistry, 64, pp.651-655, 1992.
- LiNbO3 waveguide laser with integrated coupled-cavity tuning (1994) "Tunable Coupled-Cavity Waveguide Laser at Room Temperature in Nd-diffused LiNbO3", J.Amin, M.Hempstead, J.E.Román, & J.S.Wilkinson, Optics Letters, 19, pp.1541-1543, 1994.
- Planar Er-doped optical amplifier with gain of ~3dB/cm (1996) "Ion-exchanged planar lossless splitter at 1.5μm" P.Camy, J.E.Román, F.W.Willems, M.Hempstead, J.S.Wilkinson, J.C. van der Plaats, A.M.J. Koonen, A.Béguin, C.Prel & C.Lerminiaux, Electronics Letters, 32, pp.321-323, 1996.
- Waveguide surface plasmon (SPR) detection of pesticide pollutants (1997) "Determination of Simazine in Water Samples by Waveguide Surface Plasmon Resonance", C.Mouvet, R.D.Harris, C.Maciag, B.J.Luff, J.S.Wilkinson, J.Piehler, A.Brecht, G.Gauglitz, R.Abuknesha & G.Ismail, Analytica Chimica Acta, 338, pp.109-117, 1997.
- First transition metal ion waveguide laser (1997) “Ti-Sapphire Channel Waveguide Laser by Thermal Diffusion of Titanium into Sapphire”, L.M.B.Hickey, A.A.Anderson & J.S.Wilkinson, Proc. 8th European Conference on Integrated Optics, Stockholm, April 2-4, 1997, postdeadline paper PD6.
- Trapping and propulsion of 40nm gold nanoparticles in a waveguide evanescent field (2000) “Manipulation of colloidal gold nanoparticles in the evanescent field of a channel waveguide”, L.N.Ng, B.J.Luff, M.N.Zervas & J.S.Wilkinson, Applied Physics Letters, 76, pp.1993-1995, 2000.
- Electrochemically controlled waveguide SPR (2002) “Waveguide surface plasmon resonance studies of surface reactions on gold electrodes”, J.C.Abanulo, R.D.Harris, A.K.Sheridan, P.N.Bartlett & J.S.Wilkinson, Faraday Discuss., 121, pp. 139 – 152, (2002).
- Supercontinuum generation in tantalum pentoxide waveguides (2004) “Determination of Nonlinear Refractive Index in a Ta2O5 Rib Waveguide using Self-Phase Modulation”, Chao-Yi Tai, James S. Wilkinson, Nicolas M. B. Perney, M. Caterina Netti, F. Cattaneo, Chris E. Finlayson, and Jeremy J. Baumberg, Optics Express, 12, 5110-5116, (2004).
- Waveguide sorting of microparticles (2005) “Sorting of polystyrene microspheres using a Y-branched optical waveguide”, K. Grujic, O.G. Helleso, J.P. Hole & J.S. Wilkinson, Optics Express, 13, 1-7 (2005)
- Integrated fluorescence multisensor for water pollutants @<1ng/L (2005) “Integrated optical fluorescence multisensor for water pollution”, Ping Hua, J. Patrick Hole, James S. Wilkinson, Guenther Proll, Jens Tschmelak, Guenter Gauglitz, Michael A. Jackson, Richard Nudd, Hannah M.T. Griffith, Ramadan A. Abuknesha, Joachim Kaiser and Peter Kraemmer, Optics Express, 13, 1124-1130, (2005).
- First tantalum pentoxide laser (2005) “Neodymium-doped tantalum pentoxide waveguide lasers”, B. Unal, M.C. Netti, M.A. Hassan, P.J. Ayliffe, M.D.B. Charlton, F. Lahoz, N.M.B. Perney, D.P. Shepherd, C.Y. Tai , J.S. Wilkinson & G.J. Parker, IEEE J. Quantum Electronics, 41, 1565-1573, (2005).
- Chemical assembly of microspheres on optical circuits (2009) “Manipulating spheres that sink: Assembly of micrometer size glass spheres for optical coupling”, E.J. Tull, P.N. Bartlett, G.S. Murugan, & J.S. Wilkinson, Langmuir, 25, pp. 1872-1880 (2009)
- Erbium-doped tantala nanowire laser and amplifier (2010) “Erbium doped waveguide laser in tantalum pentoxide”, A.Z. Subramanian, C.J. Oton, D.P. Shepherd & J.S. Wilkinson, IEEE Photonics Technology Letters, in press.
- Waveguide-integrated glass microsphere laser (2010)
Impact of research:
Professor James Wilkinson was a founder of Mesophotonics Ltd, a photonic crystal waveguide company, based upon photonic crystal technology in the School of Electronics and Computer Science combined with waveguide, laser and biosensor expertise from the ORC. Mesophotonics commercialised supercontinuum chips in tantalum pentoxide and SERS biosensors on microstructured surfaces.
The group aims to realise devices which can be mass-produced at low cost as the foundation of new industries meeting the needs of society for ubiquitous access to information at home, rapid detection of chemicals and biochemicals for security, food safety, pollution monitoring, disease screening and personalised medicine, and to advance basic scientific understanding for future technologies.
The group runs the Integrated Photonics cleanroom facility for optical, electronic and microfluidic device fabrication. Processes include photolithography, dip-pen nanolithography, thin-film deposition by sputtering, ion-beam deposition and evaporation, reactive ion and wet etching, ion-exchange and diffusion to 2300oC, surface metrology and scanning electron microscopy.
The group’s three optical characterisation labs include tunable titanium sapphire and diode lasers, UV laser, waveguide characterisation apparatus, optical spectrum analysers, high-sensitivity electrical impedance spectroscopy, and flow-injection analysis for biosensors.
Current research projects:
Microstructured glass & crystal photonic materials and devices – “ORC Core”.
There is increasing interest and activity in compact low-cost photonic circuits for mass-market applications such as to fibre-to-the-home (FTTH). Planar processing technology has enabled extraordinary complexity at low cost for electronic systems and has the potential to provide a revolution in mass-manufacture for all-optical systems. For this dream to be realised, materials and fabrication processes suitable for advanced photonic applications must be devised.
A key component for any optical system is a source of short pulses to act as a data signal source, clock, or frequency comb generator, and in this project we propose to realise a compact, robust, mass-producible modelocked source on a chip and demonstrate an integrated data-sampling function. Among other materials systems we are studying tantalum pentoxide (Ta2O5) as an attractive CMOS-compatible waveguide material and have demonstrated several important properties and functions for high-density photonic circuits including:
- third-order nonlinearity 33 times that of silica at a wavelength of 1.5μm (n2 ≈ 7.2 ×10-19 m2W-1)
- high refractive index (n≈2.1) yielding tight bends and high effective nonlinearity due to small spotsize
- supercontinuum generation in rib waveguides
- band-stop filtering using a photonic crystal waveguide
- suitability as a host for rare-earth ions, having exhibited gain of 2.9dB/cm and lasing at 1.5μm
- photosensitivity, allowing volume gratings with Δn ≈ 2×10-3 to be written by UV irradiation
- local diffusion of rare-earth ions into Ta2O5 films for localised gain
EPSRC; collaborations throughout the ORC and with ECS and Physics and Mesophotonics Ltd. April 2004 – March 2011.
Optical functions and lab-on-a-chip for microparticles and biomedicine
Optical tweezers are well-established as a tool for non-contact, non-destructive handling of biological materials and of inorganic nanospheres attached to biological molecules.
Recently, interest has grown in optical manipulation at surfaces potentially as part of the toolbox of the “lab-on-a-chip”. In particular, advances have been made in trapping and propulsion of metallic and dielectric micro- and nano-particles in the evanescent fields of optical waveguides, which may form part of a planar microsystem into which optical detection and spectroscopy of separated species could also be integrated. Optical waveguides embedded in surfaces represent a powerful means of controlling the distribution of optical intensity and intensity gradient at such surfaces, for particle control.
In this project, optical waveguides and waveguide devices for trapping, propulsion, sorting and analysis of biological cells are being explored. Live red blood cells have been propelled, improved microfluidics and surface modifications for use with biological cells have been devised, and micro-Raman spectroscopy is being integrated with these optofluidic systems for chemical analysis.
Research Council of Norway; collaborators University of Tromsø, Vestfold University College Norway, UC Davies. Aug 2006-July 2011.
Determination of suitable hosts for Rare-Earth doped planar upconversion waveguide lasers
The aim of this project is to identify a suitable host material for high-power visible upconversion lasers, addressing a need for suitable sources for displays.
EPSRC; Collaborators ECS Nano Group, CIP, April 2009 – April 2011.
Recent research projects:
Integrated Microsphere Planar Lightwave Circuits
Planar lightwave circuits (PLCs) offer a rugged, low-cost, mass-manufacturable route to the device requirements of future telecommunications systems. Barriers to full exploitation of conventional PLC technologies include the long path lengths required for many optical interactions and the difficulty in producing tight waveguide bends with low loss, both of which limit the density of integration and the scale of mass-manufacture.
Microsphere resonators, primarily demonstrated so far coupled to tapered fibres, have the potential to become key components in photonic circuits, providing feedback, wavelength selectivity and energy storage to allow dispersion control and enhanced nonlinearity, resonant filtering, waveguiding with low bend radius and ultra-low threshold lasing. Many of these properties stem from strengthening the interaction of light with the material through high-Q resonance.
Planar lightwave circuits present an ideal platform for the precise placement of individual microspheres or arrays of microspheres, to realise highly functional circuits in a more robust configuration than fibre devices. We propose to explore the enhancement of conventional waveguide technologies by realising microspheres from advanced glasses with tailored optical properties, positioning them in PLCs using self-assembly techniques, and realising a wide range of passive, lasing and nonlinear switching devices.
EPSRC, Prof Phil Bartlett (Chemistry), Prof MN Zervas, Prof D Hewak, SPI Lasers, Naval Research Labs, Washington. Dec 2004 – Sept 2009.
Ultrasonic manipulation and transport of DNA molecules in evanescent light fields
Ultrasonic Standing Waves (USWs) can be used to manipulate particles within a fluid. Used within chambers of a half wavelength depth or less, the ultrasonic radiation forces can move the particles either to a central plane within the chamber or to a wall of the chamber.
This project is a multidisciplinary investigation into the use of USWs in microfluidic biosensing applications. It involves the School of Engineering Sciences (SES), the Optoelectronics Research Centre (ORC) and the Microelectronics Research Centre in the Department of Electronics and Computer Science (ECS) at the University of Southampton.
The work aims to integrate optical sensing and USW excitation using techniques and materials compatible with emerging microfluidic technology. It will also use the optical/USW techniques to study and quantify the behaviour of the USW chamber, particularly with regard to the ability of "quarter wavelength" chambers to move particles to the chamber wall. The project will apply these techniques to the detection of a number of DNA sequences in a mixture. It will also investigate the feasibility of using acoustic radiation forces to interrogate single DNA sequences with a high resolution.
EPSRC, with Prof Martyn Hill (SES), Dr Nick Harris (ECS), Dr Tracy Melvin, Genetix, dstl & PointSource, Aug 2006 – Jan 2010.
Automated water analyser computer supported system
Monitoring river water quality and identifying pollution sources are major tasks in the management of the river water environment. A cost-effective, on-line water-monitoring biosensor that will simultaneously and rapidly measure a variety of organic pollutants with low molecular weight with remote control and surveillance was realised in this project. The ORC’s activities were to realise the integrated optical 32-way fluorescence immunoassay chip at the heart of the system.
EU Environment Programme; collaborators University of Tübingen, Institute of Chemistry and Environmental Chemistry IIQAB, Barcelona, King’s College London, Environmental Institute, Slovak Republic, Technologiezentrum Wasser, Germany, Siemens, Germany (SIEM) Central Research Laboratory, Ltd., Water Research Institute, Slovak Republic.
Michael Zervas, David Shepherd, Dan Hewak, Tracy Melvin, Gilberto Brambilla, Sakellaris Mailis, Peter Smith.
Profs Phil Bartlett, Tom Brown & Andrea Russell and Dr Bob Greef (Chemistry), Profs Greg Parker & Paul Lewin & Dr Nick Harris (ECS), Dr Vasilis Apostolopoulos (Physics).
Prof Dr Günter Gauglitz, Tübingen, Dr Olav Hellesø, Tromsø, Prof Francesc Diaz & Dr Joan Carvahal, URV Tarragona, Dr Fernando Lahoz, La Laguna, Dr Claudio Oton, Valencia, Dr Daniel Jaque, UAM Madrid, Dr Ram Abuknesha KCL, Prof Damia Barcelo IIQAB, Barcelona , Dr Stavros Pissadakis, FORTH, Dr Guido Perrone, Polito.
Dr Joachim Kaiser, Siemens, Mike Jackson, CRL, Kenji Kawaguchi KEM Japan, Dr Nick Barnett, Ocean Optics, Dr Martin McDonnell, dstl.
Work with us:
Please contact Professor James Wilkinson if you would like any further information about the work of our Integrated photonic devices group or would be interested to work with us.
Copyright University of Southampton 2006