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

Transcription

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

2 Introduction o o Intense laser beams Solitons Filaments and Complex spatiotemporal wave packets Sculpted Exotic beams for tamed waves Advanced materials engineering o Large volume high resolution photo-polymerization Silicon Photonics o Direct laser writing of photonic circuits in the bulk of silicon merging optics and electronics under the same platform Teaser: Passive radiative cooling o Improving the performance of photovoltaics

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

4 '' 2 E i k E E i N E 2, z 2k 2 t Kerr Plasma MPA where : N E, T N E N TN E Kerr t N E ik n a E ik n a R t E d NPlasma 1 0 C 2 2 K 2K 2 NMPA E E 1 2 at T 1 i 0 t 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) K at a t U K photons : Cross Section for Inverse Bremsstrahlung 2 K 2 2 i

5 APL 93, (2008); PRA 84, (2011)

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

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

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10 [*] 3D Writing of complex Micro- & Nanostructures but limited in volume, typically 100 μm - height I. Sakellari et. al, ACSNano, 6, 3, , 2012

11 Intensity (norm) sample 800nm, 160fs, 50Hz w: width of the primary Airy ring r 0 : radius of the primary Airy ring 1,0 0,5 Typical phase mask Intensity profile at the FT plane 100μm Ring-Airy propagation dynamics 100μm 0, Z(mm)

12 Intensity (norm) By adjusting the w and/or r 0 parameters of the primary ring, using the appropriate phase mask, the focus position can be manipulated in real time with the SLM. 1,0 Threshold Line 0,5 0, Z(mm) Intensity profiles of ring-airy beams as captured by the CCD at the FT plane Experimental intensity distributions (normalized values) of the ring-airy beams along the propagation axis

13 Focal voxel aspect Ratio comparative curves In an MPP application the polymerization takes place only at areas where the intensity is high enough. We used the 80% of the peak intensity distribution as a threshold. The ring Airy beams keep the voxel aspect ratio almost invariant! The voxel aspect ratio for Bessel beams is increasing as the beam focus is pushed further away. Spot size Focal volume FWHM Longitudinal size of Focus Focus Aspect Ratio: Focus Diameter Optica 3, (2016)

14 Optica 3, (2016)

15 Aspect ratio ~ 20000μm 4μm BurjKhalifa, Dubai

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17 Laser Matter Interactions: from fundamental studies to innovative laser processing Advanced knowledge on propagation and laser materials interaction (metals, semiconductors and dielectrics), I <10 19 W/cm 2 Development of new photonic processes New materials, new features. Higher synergy between IESL - LP3 and their organizations Access to complementary equipment Increased international visibility Strengthening of AMU & FORTH s relations within the Mediterranean region Coordinators: Mark Sentis (LP3) & Stelios Tzortzakis (IESL)

18 The road from this

19 To this The 50 Gbps Si Photonics Link

20 Experimental holographic setup Excellent agreement between our simulations and experimental results

21 The problem is projected to a stretched spacetime one such that it becomes paraxial! Excellent agreement between our simulations and experimental results

22 To date all attempts to modify the bulk of Si using femtosecond pulses have failed! Why? Two-photon absorption and defocusing in plasma lead to the depletion of the pulse energy on the way to focus.

23 Induce permanent index modification in the bulk of Si using extreme localization of light in space and time. Took 20 years to reach this milestone from the time of the first demonstration in the bulk of glasses! Nat. Commun. 8, 773 (2017)

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25 Radiative cooling: Dissipate excess heat into remote heat sinks via thermal radiation. Materials: Combination of natural and artificial materials, like metamaterials. Application in photovoltaic cells: reduced temperature of operation, resulting in higher performance and longer lifetimes. A joint research project between FORTH and Texas A&M University, funded by Qatar Foundation.

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