Stelios Tzortzakis. Science Program, Texas A&M University at Qatar Institute of Electronic Structure and Laser, FORTH, & University of Crete, Greece

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1 University of Crete Stelios Tzortzakis Science Program, Texas A&M University at Qatar Institute of Electronic Structure and Laser, FORTH, & University of Crete, Greece

Introduction o o THz science - Motivation Nonlinear Laser propagation: Solitons, Filaments and Light Bullets Tailored strong THz fields from filaments o o Understanding the physics and the scaling

2 Introduction o o THz science - Motivation Nonlinear Laser propagation: Solitons, Filaments and Light Bullets Tailored strong THz fields from filaments o o Understanding the physics and the scaling laws Controlling the spatial and temporal shape, the power and the polarization Advanced sculpturing of strong laser fields o o o With photonic lattices and exotic waves Remote generation of high THz powers with exotic beams Strong THz fields from liquids

4 Security Medical Drugs detection Picture from Qinetiq Molecular rotations Hydrogen Bonds, Torsions, collective vibrational modes From THz Network Kodo Kawase group, in Sendal, Japan Spectral fingerprints in the THz region. Collective (roto-vibrational) modes. Distinguish polymorphs. Water strongly absorbs the THz. 4 Plastic, paper, clothes are transparent in the THz region.

5 Projected properties of THz sources in the near future: ultrashort (<100fs) quasi-dc electric and magnetic fields with strengths in the GV/cm and the kilo-tesla regime. Nonlinear THz spectroscopy Acceleration of electrons and ions Matter phase-transitions Ionization (field/impact) Mode selective chemistry Spin control and magnetic switching

6 Photo-ionization of air Photoconductive effect Photomixing of CW lasers Optical parametric conversion Broadband sources (pulsed) THz science Narrowband sources (CW) Optical rectification Surface field emitters Free Electron Lasers Synchrotrons Quantum cascade Lasers Schottky diodes Vacuum tubes Gyroton

$diffraction$ $Diffraction$

7 Spatial beam profile and diffraction Temporal profile and dispersion Diffraction Dispersion

$Self-focusing (Kerr effect) compensates diffraction$ Temporal Soliton A wavepacket which is at the same

8 Self-focusing (Kerr effect) compensates diffraction Spatial Soliton Kerr effect compensates dispersion Temporal Soliton A wavepacket which is at the same time a spatial and a temporal soliton is called a Light Bullet

9 Dynamic equilibrium in space and time between Kerr effect and ionization ionization Kerr effect

10 '' 2 E i k E 2 E i N E, 2 z 2k 2 t Kerr Plasma MPA where : N E, T N E N TN E Kerr Plasma t N E ik n a E ik n a R t E d N 0 C 2 1 NMPA E E 2 T 1 i 0 t 2 K 2K 2 1 at K K 0 at K : Cross Section for Multi Photon Ionization K with rate W for K k n Ui 1 MPI 0 I K 0 0 C C 1 0 C Unidirectional Pulse Propagation Equation (UPPE) 2 K 2 2 K at a t U K photons : Cross Section for Inverse Bremsstrahlung i

11 Appl. Phys. Lett. 93, (2008) Phys. Rev. A 84, (2011)

13 o o o Highest THz peak intensity: ~MV/cm (comparable with free electron lasers) Bandwidth: >50THz (unique) Tunability (filamentation tailoring): of energy, bandwidth and polarization (unique)

14 plasma density distribution generated spectrum THz l(r,r') THZ far field intensity Realistic broadband THz radiation Phase changes by the plasma Realistic symmetric/asymmetric plasma distributions Realistic electron densities A. Gorodetsky et al., Phys. Rev. A 89, (2014) Y. S. You et al. PRL 109, (2012)

15 THz intensity, a.u Angle( o ) 3mm 5mm 8mm 12mm 18mm Filament length THz intensity, a.u e16 1e17 2e17 5e17 conical angle filament (mm) 5e16 1e17 5e17 Both Angle ( o ) Filament density

THz intensity (a.u.) 1 0.8 0.6 0.4 0.2 0 0 2 4 6 8 10 Angle ( o ) 2.1mm 7.3mm 18.3mm A. Gorodetsky et al., Phys. Rev.

16 THz intensity (a.u.) Angle ( o ) 2.1mm 7.3mm 18.3mm A. Gorodetsky et al., Phys. Rev. A 89, (2014) conical angle ( o ) N, cm -3 experiment model filament length (mm) 4 2 length (mm)

17 THz intensity (a.u.) Angle ( o ) 2.8 mm 10.5 mm 17.7 mm A. Gorodetsky et al., Phys. Rev. A 89, (2014)

19 J. M. Manceau et al, Opt. Lett. 35, (2010)

20 Wavefront distortions Asymmetric Symmetric Gradient Uniform J. M. Manceau, et al, Opt. Lett. 34, (2009)

21 The induced phase change can be calculated :

22 Phase variation d ( n n ) 2 / c n From linear to fully circular J.-M. Manceau, et al Opt. Express 18, (2010)

$Periodic spatial refractive$ material Square Lattice n x, y

24 Periodic spatial refractive index modulation of the material Square Lattice n x, y Can Photonic Lattices control filaments?

25 w/o lattice Intense light bullet w/ lattice First theoretical prediction of light bullets in the normal dispersion regime! Opt. Express 19, (2011)

26 Experiments in solids Experiments in liquids w/o lattice w/o lattice w/ lattice w/ lattice Phys. Rev. Lett. 109, (2012); Physics Focus Appl. Phys. Lett. 103, (2013)

28 Bessel beam Airy beam Parabolic beam

i 1 2 2 s 2 0 Normalized paraxial propagation equation Non-dispersive solution in 1D

29 i s 2 0 Normalized paraxial propagation equation Non-dispersive solution in 1D 2 3 (, s) Ai( s ( / 2) ) exp[ i( s / 2 /12)] x-y beam profile Airy propagation (x-z)

30 Phys. Rev. Lett. 105, (2010) Airy 3 light bullet

31 Opt. Lett. 36, 1842 (2011) Exciting candidates for a variety of applications, as in bio-medicine, laser nanosurgery and optical lithography (e.g. photopolymerization)

32 Opt. Lett. 36, 1842 (2011) Linear Space Nonlinear In the nonlinear regime they transform to intense light bullets Nature Communications 4:2622 (2013) Space-time evolution

33 experiment simulation From localized spots to localized strings of light Opt. Lett. 41, (2016) Editors Pick

35 Radial Lattice n r

36 w/o lattice w/ lattice Opt. Lett. 39, (2014)

37 A radially decreasing Δn lattice or even a single ring results in interesting propagation features Lattice period: 350 μm Lattice period: 250 μm Opt. Lett. 39, (2014)

39 Remote tailored strong THz emission

40 Optica 3, (2016)

42 Nature Communications, to appear (2017)

Tailored strong THz fields from filaments o o o Understanding the physics and the scaling laws Plasma density, uniformity and length Controlling the spatial and temporal shape, the power and the

43 Tailored strong THz fields from filaments o o o Understanding the physics and the scaling laws Plasma density, uniformity and length Controlling the spatial and temporal shape, the power and the polarization Advanced sculpturing of strong laser fields o o o o o With photonic lattices and exotic waves Uniform longer plasma filaments Remote generation of high THz powers with exotic beams A pathway to follow Exciting opportunities using high peak power mid- and farinfrared lasers and filaments, as well as dense media

44 UNIS group: V. Fedorov T. Koulouklidis H. Zhang Ch. Daskalaki M. Loulakis D. Papazoglou Funding University of Crete Collaborators: Farsari / Manousidaki, FORTH Grojo / Chanal, Univ. of Marseille Zacharakis / Di Batista, FORTH Tsironis / Mattheakis, UoC A. Couairon, Ecole Polytechnique D. Christodoulides, CREOL Moloney / Kolesik, Arizona X.-C. Zhang, Rochester

Stelios Tzortzakis. Science Program, Texas A&M University at Qatar Institute of Electronic Structure and Laser, FORTH & University of Crete, Greece

Stelios Tzortzakis. Science Program, Texas A&M University at Qatar Institute of Electronic Structure and Laser, FORTH & University of Crete, Greece University of Crete Stelios Tzortzakis Science Program, Texas A&M University at Qatar Institute of Electronic Structure and Laser, FORTH & University of Crete, Greece Introduction o o Intense laser beams