1. TERASPARC: Terahertz Radiation @ the Free-Electron Laser Stefano Lupi (on behalf of the TERASPARC team) Dipartimento di Fisica, Sapienza Università di Roma and INFN

2. Acknowledgments TERASPARC collaboration: INFN LNF/Roma1-2: M. Bellaveglia, E. Chiadroni, P. Calvani, M. Castellano, A.Cianchi, L. Cultrera, G. Di Pirro, M. Ferrario, L. Ficcadenti, G. Gatti, O.Limaj, B. Marchetti, A. Mostacci, E. Pace, A. R. Rossi, L. Palumbo, C. Vaccarezza, and the technical staff: F. Anelli, S. Fioravanti, R. Sorchetti; INFN Torino-Catania:G. Ghigo, R. Gerbaldo, L. Gozzelino, F. Laviano ELETTRA: A. Perucchi LFN-CNR: M. Ortolani

3. The Terahertz gap 0.1 THz – 5 THz No electronics, few microwaves generators Vanishing thermal power, few tunable and pulsed lasers.

4. THz Science and Technology Superconductivity Energy gap Symmetry of the order parameter Direct determination of the superfluid density Dynamics of Cooper pairs Low-dimensional materials Dimensionality crossover Non-Fermi liquid normal states Broken symmetry ground states Coherent Phase Transitions Polarons Structural Phase Transitions Magnetic sub-ps Dynamics Condensed Matter Physics Life Sciences Macromolecules conformation Secondary and tertiary structure Coherent dynamic development Imaging 3D tomography of dry tissues Near-field sub-wavelenght spatial resolution Polar liquids Hydrogen bond Van der Waals interactions Acoustic-Optic phonon mixing in water Solutions Static and dynamic interactions between solvated ions and solvent Physical and Analytical Chemistry New Technologies THz technologies Array THz detectors Metamaterials Medical diagnostic Skin cancer detection Industrial production Material inspection Production line monitoring Defense industry/Homeland security Detection of explosives and biohazards

5. Available THz sources Terahertz Lasers Quantum Cascade Lasers (>1 THz); Si- and Ge-lasers (>1.5 THz); Gas-based lasers (emission only at some given frequencies); Sources based on electron bunch acceleration Narrow Band Stanford (>3 THz); Far-Infrared FELs: FELIX, FELBE; ENEA compact FEL; Far-IR undulator @ FLASH (Hamburg); Backward-wave oscillators; Broad Band Laser Amplifiers: plasma and no linear crystals (no user facility), Coherent Synchrotron Radiation @ III Generation Machines FEL-based Broad Band (femto-second pulsed) THz Sources

6. Coherent THz Radiation

7. Sub-ps e-bunches: X-UV-VIS FEL machines routinely produce sub-ps e-bunches.Those bunches emit coherent THz and far-IR radiation and also useful IR-VIS radiation Key points for THz coherent emission

8. Diagnostic and Matching SPARC OVERVIEW

9. Performances Achieved E. Chiadroni et al, Unpublished

10. THz-Dream 1.THz coherent emission covering a large spectral range: 0.1 to 30 THz; 2.THz pulse duration lower than 50 fs; 3.Energy/pulse in the 10-100 mJ range; 4.Far-IR, Mid-IR and VIS probe; 1.Optical coupling between the laser and the THz pulse: THz pump-X probe;

11. High Energy/Pulse THz Pump- THz Probe non-linear time-domain experiments (THz Pump and IR+VIS Probes using IR+VIS emissions) Average Energy (Power) Frequency-Domain Spectroscopy THz Experiments

12. Ultrashort, intense (E>1 MV/cm)THz pulses needed! E c critical field for the SC Superconducting film, T < T c The high E (~MV) THz field may induce currents exceeding the critical superconducting current (breaking the Superconducting State with an Electric Field) New kind of transient excitations (out-of-equilibrium supercurrent) avoiding heating effects; How this no-linear state recorces to equilibrium? High E field associated to the THz pulse

13. Magnetic Dynamics with THz pulses A sub-ps THz pulse associates to an E field of 1 MV/cm a B field ~ 0.5 T THz induced magnetic transitions THz Time Resolved Electron Spin Resonance

14. Conformational Collective modes of macromolecules water Conformational dynamics of DNA, proteins, lipids, result in collective THz modes. Structural changes are critically important in biological activity thus, if these modes are frozen out, the ability to change structure is lost. Dynamical evolution from disordered conformational states to ordering Large pump THz E field may coherent induce conformational ordering and THz probe may measure its temporal evolution

15. Femto-Chemistry THz is sensitive to interaction time between a molecule and the surrounding solvent on sub-ps scale Standard high-frequency time-resolved experiments: excite in the UV-VIS a soluted molecule -----> probe in the THz the dynamical effects on solvent High THz fields may induce molecular orientational motion or interionic motion leading to changes in local structures of solvent. This may coherent induce chemical reactions that can be measure with a VIS-UV probe.

16. Imaging vs Penetration

17. Chemical Pharmaceutic recognition Background absorption

18. Imaging of Bio-materials, molecular in-vivo imaging of pathogenesis THz do not subject a biological tissue to harmful radiation and may provide both imaging and spectroscopic information on biological materials. Needs of: 1.High S/N ratio 2.High acquisition rate and resolution 3.THz database for biological tissues 4.High power to increase sensing and penetration 5.Near-field imaging to increase spatial resolution (up to now 10 microns resolution has been obtained) T. Lffler et al, Optics Express 9, 616 (2001) Ferguson et al, Nature Materials1, 26 (2002) X.-C Zhang Phys. Med. Biol. 47, 3667 (2002)

19. Far-infrared detector IEEE Sensors 10 (2010) 863 Physica C 470 (2010) 918 Superconductor Science and Technology 23 (2010) 125008 Detector layout YBa 2 Cu 3 O 7-x High T C Superconducting YBa 2 Cu 3 O 7-x film patterned by photolithography and Heavy-Ion Lithography Real-time response Far-infrared Beams to Far-infrared Beams ( > 60  m) Portable detector housing LN 2 portable cryostats QCL test source detector housing 20 cm

20. BEAM EXPANDER BEAM CONDENSER THz FOCAL PLANE ARRAY THz POINT-LIKE SOURCE TARGET II. DEVELOPMENT OF TERAHERTZ CAMERAS Detectors for the 0.5-5 THz range: Fast response time (microsecond) for multiplexing readout Monolithic, Fabricated with industrial processes Array prototype fabrication at CNR-IFN in Rome Nanofabrication facility: Clean room Electron beam lithography Thin film deposition Deep etching IFN-CNR M. Ortolani, R. Leoni, V. Foglietti, S. Cibella, A. Di Gaspare, E. Giovine, G. Torrioli, F. Evangelisti La Sapienza P. Calvani, S. Lupi, A. Nucara ENEA Frascati A. Doria, G.P. Gallerano, E. Giovenale, A. Petralia, I. Spassovsky, G. Messina SELEX S.I. S.p.A. A. Cetronio, M. Peroni, C. Lanzieri (Finmeccanica group) ERAes s.r.l. B. Mencagli, G. Scrascia, M. Grego