Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 1 Terahertz Research in a European Context Martyn Chamberlain Institute of Microwaves & Photonics The University of Leeds Leeds, UK. THz- Bridge Workshop, Capri, October 2002

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 2 Co-Authors n The Terahertz Imaging Group at Leeds, in the Institute of Microwaves and Photonics and the Medical School: – Liz Berry, Tony Fitzgerald, James Hanley, Mike Smith, Sarah Thornton, Gillian Walker. – Andrew Foulds, Bob Miles, Mira Naftaly, Michael Stone, Nick Zinov’ev.

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 3 Acknowledgements n Numerous authors, for kind permission to use material. n Colleagues within Teravision and Interact. n Prof. Shervanthi Homer-Vanniasinkam n Our funding agencies: EPSRC, EU.

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 4 TERAVISION “Realisation of a compact, efficient Terahertz Imaging system for clinical evaluation” n Leeds (Image Processing, “Owners manual”) n TU Delft (Improved Detection, Acquisition) n Femtolasers (Compact Ti:Sapphire lasers) n Frankfurt University (CW Route) n TU Vienna (THz Generation) n TeraView Ltd. (Compact System Realisation)

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 5 Content n The closing gap: recent source developments. n Some relevant systems: for imaging, sensing and microscopy. n Applications: medical imaging, bioscience, surveillance. n Prospects for future European work.

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 6 The Closing Gap: Recent Source Developments.

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 7 Cascade Laser Developments Small THz sources are difficult to make: both electronic and optical routes pose problems. Cascade lasers were first developed for near infrared. Emission occurs as carriers move between subband states Courtesy EH Linfield

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 8 Cascade Laser Developments 3.5THz operation recently reported. Works up to 67K. mW output Pulsed and CW. Achieved by EU WANTED Consortium. Courtesy EH Linfield

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 9 A University of Lille planar InP HBV diode pair and RF performance. This is the first HBV device to break the 10mW barrier Work performed in the INTERACT grouping. All-Electronic THz Source Development Courtesy: Didier Lippens, Chris Mann

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 10 Other Source Developments Superlattice Oscillators: 150GHz, mW power. (Schomburg, Regensburg.) Structures for CW mixing (Lippens, Lille) Advanced semiconductor structures for pulsed imaging systems ( Linfield, Cambridge and Unterrainer, Wien) Courtesy: Didier Lippens

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 11 Intra-Cavity THz Generation Use of an intra-cavity generator and a saturatable absorber can deliver THz pulses from one unit. Courtesy: Charley Unterrainer and Juraj Darmo

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 12 Large Scale Facilities for THz The FELIX laser is ideal for pump-probe studies of carrier dynamics.

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 13 n “Compact” Terahertz Systems for: – Imaging – Sensing – Microscopy.

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 14 Delay Stage X-Y translation Image formation and processing Pulsed Laser THz Source Coherent detection Basic Hardware: THz Pulsed Imaging System

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 15 Pulsed Terahertz Imaging Systems Courtesy: Teraview Ltd.

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 16 State of the Art System Performance Dynamic range One pixel in 20ms: image ( 1” square) in 250s. Penetration: 4-5mm moist tissue. Reflection images of in vivo subjects. Many new system developments on the way. Courtesy:Paul Planken

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 17 CW Imaging Courtesy: Hartmut Roskos

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 18 Terahertz Microscopy  component localized near metal tip (100) orientation: measure only  component probe TH z Increasing the resolution using (100) crystals THz spot size of 10  m, useful for THz microscopic imaging Courtesy: Paul Planken

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 19 Terahertz Microscopy Near field spectroscopy system. Study molecules in solution at THz. /100 Resolution BWO sources. Courtesy: Martin Dressel

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 20 n Applications: – Medical Imaging – Bioscience – Surveillance

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 21 Medical Images Pulse AmplitudeTime Delay Pulse Width  /(n - 1) Basal Cell Carcinoma Images: Leeds Teravision Group

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering THz 1.0THz 2.0THz Medical Images Transmittance Phase Change (from FT) Multiple Frequency Comparison Melanoma Leeds Teravision Group

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 23 Medical Images Leg Artery spectra and Images: Leeds Teravision Group

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 24 Medical Images Leeds Teravision Group

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 25 Medical Images Courtesy: Ruth Woodward, TeraView Ltd. BCC data obtained using time-delay. 4mm TPP, t = -1.74ps x d2 d1 i2 i1 n2 n1 4mm

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 26 Tumours Courtesy: Martin Koch Medical Images CW Imaging System, Bolometer Detection

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 27 Bioscience Applications Courtesy: M.Koch and P. Uhd-Jepsen DNA has strong THz signatures

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 28 Bioscience Applications Detect mutations in DNA by shift in resonance frequency. Highly sensitive ( fmol) Label free assay Courtesy: Peter Haring Bolivar. National/Land funding

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 29 Sensing & Surveillance Courtesy: Paul Planken, D. Grischkowsky

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 30 Prospects for future European work.

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 31 Existing EU Projects n INTERACTION (Bob Miles, Leeds) n SHINE (Doug Paul, Cambridge) n Terahertz-Bridge (Gian-Piero Gallerano, Frascati) n Teravision, Teravision-EAST (Martyn Chamberlain, Leeds) n WANTED (Edmund Linfield, Cambridge) n PLUS: Support for Large Scale Facilities

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 32 Prospects for Framework VI n Workprogrammes will soon be promulgated. n Integrated Project or Network of Excellence? n Important to demonstrate integration. n More flexible planning possible. n Larger consortia and budgets. n Plans for two THz Networks known!

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 33 TeraNova

Institute of Microwaves and Photonics School of Electronic and Electrical Engineering 34 Conclusions n Terahertz is alive and well and living in Europe! n Both electronic and optical routes are being pursued. n Variety of systems in development. n Variety of promising applications. n Commercial interest is growing. n Prospects are good for the future!