In the UNIS group we are working in the field of intense ultrashort laser pulse interaction with matter. Our activities are grouped in 3 directions.

We study the nonlinear propagation of intense ultrashort laser pulses in transparent media and related filamentation processes. We develop experimental tools to monitor the interaction of the strong laser fields with the matter and also ways to control the nonlinear propagation through the use of "exotic" wavepackets or photonic lattices.

In the second direction we develop novel strong field THz sources. We are investigating mainly filamentation based approaches and explore novel ways for increasing the source peak power. We are proposing ways of taming the source properties through filamentation tailoring methods or using novel artificial materials like metamaterials and eutectics. With the available THz intensities we explore the new era of nonlinear THz optics.

Finally, in the third direction we use photonic lattices for a number of applications. From the control of the nonlinear propagation, to the study of complexity physics and quantum information and quantum analogs.

In our research we are dealing with both fundamental science aspects as well as technological applications. The polyvalent nature of our facility allows studies in cross-disciplinary science including physics, chemistry, materials science and bio-medicine.




  •  Rozhdestvensky honorary medal from the Russian Optical Society (2013) for Prof. Stelios Tzortzakis

  •  Marie Curie Excellence Grant (~2M€ ; 2006-2010)  Prof. Stelios Tzortzakis

Research Highlights

  • Demonstration of a sub-picosecond all-optical THz switch based on three-dimensional (3D) terahertz meta-atoms (link)

  • Development of a novel THz source that exceeds in power performance and conversion efficiency any other THz source known to date (link)

  • Crossing the threshold of ultrafast 3D laser writing in bulk silicon (link)

  • Generation of highly efficient broadband terahertz pulses from ultrashort laser filamentation in liquids (link)

  • Theoretical and experimental demonstration that the harmonics from abruptly autofocusing ring-Airy beams preserve the phase distribution of the fundamental beam. even after focusing these beams still spatially overlap, surprisingly over elongated focal volumes (link)

  • Numerical and experimental demonstrations of the accelerating Airy and ring-Airy beams that show that the waves are a superposition of twin waves, which are conjugate to each other under inversion of the propagation direction, known as Janus Waves (link)

  • Generation of THz waves that has more than 5 times the pulse energy of THz waves created with standard Gaussian beams, by using ring-Airy beams (link)

  • Accessing Extreme Spatiotemporal Localization of High-Power Laser Radiation through Transformation Optics and Scalar Wave Equations (link)

  • Demonstration that the focus position of abruptly autofocusing ring Airy beams can be tailored to cover an extended range, maintaining at the same time an almost invariant focal voxel (link)

  •  First demonstration of nonlinear intense “light bullets” in normal dispersion media (link)

  • First demonstrations of dynamical filamentation tailoring in various media and photonic lattices (link)

For more info, please don't hesitate to visit our group web page https://unis.iesl.forth.gr/


Efficient Broadband and Powerful Terahertz Sources
Food safety traceability using advanced non-invasive spectroscopic techniques
Observation of extremely efficient terahertz generation from mid-infrared two-color laser filaments
A. D. Koulouklidis, C. Gollner, V. Shumakova, V. Yu. Fedorov, A. Pugžlys, A. Baltuška, S. Tzortzakis
Nature Communications, Volume:11, Issue:1, Page:1, Year:2020, DOI:doi.org/10.1038/s41467-019-14206-x
Phase Memory Preserving Harmonics from Abruptly Autofocusing Beams
A. D. Koulouklidis, D. G. Papazoglou, V. Y. Fedorov, and S. Tzortzakis
Phys.Rev.Lettters, Volume:119, Page:223901, Year:2017, DOI:https://doi.org/10.1103/PhysRevLett.119.223901
Janus Waves
D. G. Papazoglou, V. Y. Fedorov, and S. Tzortzakis
Janus Waves, Volume:41, Page:4656-4659, Year:2016, DOI:https://doi.org/10.1364/OL.41.004656
Optimal wavelength for two-color filamentation-induced terahertz sources
Vladimir Yu Fedorov, Stelios Tzortzakis
OSA, Volume:26, Issue:24, Page:31150-31159, Year:2018, DOI:https://doi.org/10.1364/OE.26.031150
Extreme THz fields from two-color filamentation of midinfrared laser pulses
Vladimir Yu Fedorov, Stelios Tzortzakis
PHYSICAL REVIEW A, Volume:97, Issue:6, Page: 063842, Year:2018, DOI:https://doi.org/10.1103/PhysRevA.97.063842
Ring-Airy beams at the wavelength limit
Manousidaki, Maria; Fedorov, Vladimir Yu; Papazoglou, Dimitrios G; Farsari, Maria; Tzortzakis, Stelios
Optics Letters, Volume:43 , Issue:5, Page:1063-1066, Year:2018, DOI:doi.org/10.1364/OL.43.001063
Highly efficient broadband terahertz generation from ultrashort laser filamentation in liquids
Indranuj Dey, Kamalesh Jana, Vladimir Yu. Fedorov, Anastasios D. Koulouklidis, Angana Mondal, Moniruzzaman Shaikh, Deep Sarkar, Amit D. Lad, Stelios Tzortzakis, Arnaud Couairon, G. Ravindra Kumar
Nature Communications, Volume:8, Issue:1184, Year:2017, DOI:https://doi.org/10.1038/s41467-017-01382-x
Crossing the threshold of ultrafast laser writing in bulk silicon
Margaux Chanal, Vladimir Yu. Fedorov, Maxime Chambonneau, Raphaël Clady, Stelios Tzortzakis, David Grojo
Nature Communications, Volume:8, Issue:773, Year:2017, DOI:https://doi.org/10.1038/s41467-017-00907-8
Non-diffracting states in one-dimensional Floquet photonic topological insulators
Matthieu Bellec, Claire Michel, Haisu Zhang, Stelios Tzortzakis, Pierre Delplace
EPL, Volume:119, Issue:1, Page:14003, Year:2017, DOI:https://doi.org/10.1209/0295-5075/119/14003
Invariant superoscillatory electromagnetic fields in 3D-space
KG Makris, DG Papazoglou, S Tzortzakis
Journal of Optics, Volume:19, Issue:1, Page:014003, Year:2016, DOI:https://doi.org/10.1088/2040-8986/19/1/014003
Tailored light sheets through opaque cylindrical lenses
Diego Di Battista, Daniele Ancora, Haisu Zhang, Krystalia Lemonaki, Evangelos Marakis, Evangelos Liapis, Stelios Tzortzakis, Giannis Zacharakis
OPTICA, Volume:3, Issue:11, Page:1237-1240, Year:2016, DOI:https://doi.org/10.1364/OPTICA.3.001237
THz generation by two-color femtosecond filaments with complex polarization states: four-wave mixing versus photocurrent contributions
VY Fedorov, AD Koulouklidis, S Tzortzakis
Plasma Physics and Controlled Fusion, Volume:59, Issue:1, Page:014025, Year:2016, DOI:https://doi.org/10.1088/0741-3335/59/1/014025
Accessing extreme spatiotemporal localization of high-power laser radiation through transformation optics and scalar wave equations
V Yu Fedorov, M Chanal, D Grojo, S Tzortzakis
PHYSICAL REVIEW LETTERS, Volume:117, Issue:4, Page:043902, Year:2016, DOI:https://doi.org/10.1103/PhysRevLett.117.043902
Erratum: “Robust authentication through stochastic femtosecond laser filament induced scattering surfaces” [Appl. Phys. Lett. 108, 211107 (2016)]
H Zhang, D Di Battista, G Zacharakis, S Tzortzakis
Applied Physics Letters, Volume:109, Issue:3, Page:039901, Year:2016, DOI:https://doi.org/10.1063/1.4959265
Enhanced terahertz wave emission from air-plasma tailored by abruptly autofocusing laser beams
K Liu, AD Koulouklidis, DG Papazoglou, S Tzortzakis, XC Zhang
OPTICA, Volume:3, Issue:3, Page:605-608, Year:2016, DOI:https://doi.org/10.1364/OPTICA.3.000605
Robust authentication through stochastic femtosecond laser filament induced scattering surfaces
H Zhang, S Tzortzakis
Applied Physics Letters, Volume:108, Issue:21, Page:211107, Year:2016, DOI:https://doi.org/10.1063/1.4952716
Abruptly autofocusing beams enable advanced multiscale photo-polymerization
M Manousidaki, DG Papazoglou, M Farsari, S Tzortzakis
OPTICA, Volume:3, Issue:5, Page:525-530, Year:2016, DOI:https://doi.org/10.1364/OPTICA.3.000525
Spectral bandwidth scaling laws and reconstruction of THz wave packets generated from two-color laser plasma filaments
AD Koulouklidis, V Yu Fedorov, S Tzortzakis
PHYSICAL REVIEW A, Volume:93, Issue:3, Page:033844, Year:2016, DOI:https://doi.org/10.1103/PhysRevA.93.033844
Structured adaptive focusing through scattering media
Diego Di Battista, Daniele Ancora, Haisu Zhang, Krystalia Lemonaki, Stella Avtzi, Stelios Tzortzakis, Marco Leonetti, Giannis Zacharakis
Proc. SPIE - Adaptive Optics and Wavefront Control for Biological Systems II, Volume:9717, Page:971719, Year:2016, DOI:https://doi.org/10.1117/12.2211594
Nonlinear plasma-assisted collapse of ring-Airy wave packets
Paris Panagiotopoulos, Arnaud Couairon, Miroslav Kolesik, Dimitris G Papazoglou, Jerome V Moloney, Stelios Tzortzakis
PHYSICAL REVIEW A, Volume:93, Issue:3, Page:033808, Year:2016, DOI:https://doi.org/10.1103/PhysRevA.93.033808
Extreme events in complex linear and nonlinear photonic media
M Mattheakis, IJ Pitsios, GP Tsironis, S Tzortzakis
Chaos, Solitons & Fractals, Volume:84, Page:73-80, Year:2016, DOI:https://doi.org/10.1016/j.chaos.2016.01.008
Study of THz emission from ring-Airy beam induced plasma
Kang Liu, D. G. Papazoglou, A. D. Koulouklidis, S. Tzortzakis, X.-C. Zhang
IEEE, Page:1-2, Year:2015, DOI:https://doi.org/10.1109/IRMMW-THz.2015.7327523
Fano resonances in THz metamaterials composed of continuous metallic wires and split ring resonators
Zhaofeng Li, Semih Cakmakyapan, Bayram Butun, Christina Daskalaki, Stelios Tzortzakis, Xiaodong Yang, Ekmel Ozbay
OPTICS EXPRESS, Volume:22, Issue:22, Page:26572-26584, Year:2014, DOI:https://doi.org/10.1364/OE.22.026572
Controlling high-power autofocusing waves with periodic lattices
P Panagiotopoulos, DG Papazoglou, A Couairon, S Tzortzakis
Optics Letters, Volume:39, Issue:16, Page:4958-4961, Year:2014, DOI:https://doi.org/10.1364/OL.39.004958
Physics of the conical broadband terahertz emission from two-color laser-induced plasma filaments
Andrei Gorodetsky, Anastasios D Koulouklidis, Maria Massaouti, Stelios Tzortzakis
PHYSICAL REVIEW A, Volume:89, Issue:3, Page:033838, Year:2014, DOI:https://doi.org/10.1103/PhysRevA.89.033838
A Waveguide Made of Hot Air
Arnaud Couairon, Stelios Tzortzakis
Physics, Volume:7, Issue:21, Year:2014, DOI:https://doi.org/10.1103/Physics.7.21
Experimental Demonstration of Ultrafast THz Modulation in a Graphene-Based Thin Film Absorber through Negative Photoinduced Conductivity
C. Anna Tasolamprou, D. Anastasios Koulouklidis, Christina Daskalaki, P. Charalampos Mavidis, George Kenanakis, George Deligeorgis, Zacharias Viskadourakis, Polina Kuzhir, Stelios Tzortzakis, Maria Kafesaki, N. Eleftherios Economou, M. Costas Soukoulis
ACS Photonics, Volume:6, Page:720-727, Year:2019, DOI:doi.org/10.1021/acsphotonics.8b01595
Influence of air humidity on 248-nm ultraviolet laser pulse filamentation
V. Alexey Shutov, V. Daria Mokrousova, Yu Vladimir Fedorov, V. Leonid Seleznev, E. Georgy Rizaev, V. Anna Shalova, D. Vladimir Zvorykin, Stelios Tzortzakis, A. Andrey Ionin
Optics Letters, Volume:44, Page:2165-2168, Year:2019, DOI:doi.org/10.1364/OL.44.002165
Transformation of ring-Airy beams during efficient harmonic generation
Yu V. Fedorov, G. D. Papazoglou, S. Tzortzakis
Optics Letters, Volume:44, Page:2974-2977, Year:2019, DOI:doi.org/10.1364/OL.44.002974
Long-scale multiphoton polymerization voxel growth investigation using engineered Bessel beams
Maria Manousidaki, Dimitrios G Papazoglou, Maria Farsari, Stelios Tzortzakis
Optical Materials Express, Volume:9, Issue:7, Page:2838-2845, Year:2019, DOI:https://doi.org/10.1364/OME.9.002838
Competing Nonlinear Delocalization of Light for Laser Inscription Inside Silicon with a 2-um Picosecond Laser
M. Chambonneau, L. Lavoute, D. Gaponov, Y. V. Fedorov, A. Hideur, S. Février, S. Tzortzakis, O. Utéza, D. Grojo
Physical Review Applied, Volume:12, Issue:2, Page:024009, Year:2019, DOI:doi.org/10.1103/PhysRevApplied.12.024009
Tight focusing of electromagnetic fields by large-aperture mirrors
E. D. Shipilo, A. I. Nikolaeva, Yu V. Fedorov, S. Tzortzakis, A. Couairon, A. N. Panov, G. O. Kosareva
Physical Review E, Volume:100, Page:033316, Year:2019, DOI:doi.org/10.1103/PhysRevE.100.033316
Laser‐Driven Strong‐Field Terahertz Sources
András József Fülöp, Stelios Tzortzakis, Tobias Kampfrath
Advanced Optical Materials, Volume:8, Issue:3, Page:1900681, Year:2019, DOI:doi.org/10.1002/adom.201900681
3D holographic light shaping for advanced multiphoton polymerization
Maria Manousidaki, G. Dimitrios Papazoglou, Maria Farsari, Stelios Tzortzakis
Optics Letters, Volume:45, Page:85-88, Year:2020, DOI:doi.org/10.1364/OL.45.000085
Passive radiative cooling and other photonic approaches for the temperature control of photovoltaics: a comparative study for crystalline silicon-based architectures
George Perrakis, C. Anna Tasolamprou, George Kenanakis, N. Eleftherios Economou, Stelios Tzortzakis, Maria Kafesaki
Optics Express, Volume:28, Page:18548-18565, Year:2020, DOI:doi.org/10.1364/OE.388208
Ultraviolet radiation impact on the efficiency of commercial crystalline silicon-based photovoltaics: a theoretical thermal-electrical study in realistic device architectures
George Perrakis, C. Anna Tasolamprou, George Kenanakis, N. Eleftherios Economou, Stelios Tzortzakis, Maria Kafesaki
OSA Continuum, Volume:3, Issue:6, Page:1436-1444, Year:2020, DOI:doi.org/10.1364/OSAC.388905
Powerful terahertz waves from long-wavelength infrared laser filaments
Yu Vladimir Fedorov, Stelios Tzortzakis
Light: Science & Applications, Volume:9, Page:186, Year:2020, DOI:doi.org/10.1038/s41377-020-00423-3
Impact of gas dynamics on laser filamentation THz sources at high repetition rates
D. Anastasios Koulouklidis, Christina Lanara, Christina Daskalaki, Yu Vladimir Fedorov, Stelios Tzortzakis
Optics Letters, Volume:45, Page:6835-6838, Year:2020, DOI:doi.org/10.1364/OL.413538
Taming Ultrafast Laser Filaments for Optimized Semiconductor–Metal Welding
Maxime Chambonneau, Qingfeng Li, Yu. Vladimir Fedorov, Markus Blothe, Kay Schaarschmidt, Martin Lorenz, Stelios Tzortzakis, Stefan Nolte
Laser & Photonics Reviews, Volume:15, Page:2000433, Year:2021, DOI:doi.org/10.1002/lpor.202000433
Femtosecond Broadband Frequency Switch of Terahertz Three-Dimensional Meta-Atoms
Paul Goulain, D. Anastasios Koulouklidis, Jean-Michel Manceau, Christina Daskalaki, Bruno Paulillo, Kenneth Maussang, Sukhdeep Dhillon, R. Joshua Freeman, Lianhe Li, H. Edmund Linfield, Stelios Tzortzakis, Raffaele Colombelli
ACS Photonics, Volume:8, Page:1097-1102, Year:2021, DOI:doi.org/10.1021/acsphotonics.0c01802
Combined nano and micro structuring for enhanced radiative cooling and efficiency of photovoltaic cells
George Perrakis, C. Anna Tasolamprou, George Kenanakis, N. Eleftherios Economou, Stelios Tzortzakis, Maria Kafesaki
Scientific Reports, Volume:11, Page:11552, Year:2021, DOI:doi.org/10.1038/s41598-021-91061-1
Transverse ultrafast laser inscription in bulk silicon
M. Chambonneau, M. Blothe, Q. Li, Yu V. Fedorov, T. Heuermann, M. Gebhardt, C. Gaida, S. Tertelmann, F. Sotier, J. Limpert, S. Tzortzakis, S. Nolte
Physical Review Research, Volume:3, Issue:4, Page:043037, Year:2021, DOI:doi.org/10.1103/PhysRevResearch.3.043037
In-Volume Laser Direct Writing of Silicon—Challenges and Opportunities
Maxime Chambonneau, David Grojo, Onur Tokel, Ömer Fatih Ilday, Stelios Tzortzakis, Stefan Nolte
Laser & Photonics Reviews, Volume:15, Issue:11, Page:2100140, Year:2021, DOI:doi.org/10.1002/lpor.202100140
Terahertz emission from curved plasma filaments induced by two-color 2D Airy wave packets
D. Anastasios Koulouklidis, Dimitris Mansour, Yu Vladimir Fedorov, G. Dimitris Papazoglou, Stelios Tzortzakis
Optics Letters, Volume:47, Page:1271-1274, Year:2022, DOI:doi.org/10.1364/OL.445494
Altering the Surface Properties of Metal Alloys Utilizing Facile and Ecological Methods
Franceska Gojda, Michalis Loulakis, Lampros Papoutsakis, Stelios Tzortzakis, Kiriaki Chrissopoulou, H. Spiros Anastasiadis
Langmuir, Volume:38, Page:4826-4838, Year:2022, DOI:doi.org/10.1021/acs.langmuir.1c03431
Submicron Organic–Inorganic Hybrid Radiative Cooling Coatings for Stable, Ultrathin, and Lightweight Solar Cells
George Perrakis, C. Anna Tasolamprou, George Kenanakis, N. Eleftherios Economou, Stelios Tzortzakis, Maria Kafesaki
ACS Photonics, Volume:9, Page:1327-1337, Year:2022, DOI:doi.org/10.1021/acsphotonics.1c01935
Advanced Multiphoton Polymerization using Tunable Shaped Laser Wavepackets
Maria Manousidaki, Vladimir Yu. Fedorov, Dimitrios G. Papazoglou, Maria Farsari, and Stelios Tzortzakis
Year: 2018, ISBN:978-1-943580-46-0
Precise Holographic Measurements Reveal High Electron Densities in Mid-Infrared Laser Filaments in Air
D. G. Papazoglou, V. Shumakova, S. Ališauskas, V. Yu. Fedorov, A. Pugžlys, A. Baltuška, and S. Tzortzakis
Year: 2018, ISBN:978-1-943580-42-2
Observation of Strong THz Fields from Mid-Infrared Two-Color Laser Filaments
A. D. Koulouklidis, C. Gollner, V. Shumakova, V. Yu. Fedorov, A. Pugžlys, A. Baltuška, and S. Tzortzakis
Year: 2018, ISBN:978-1-943580-42-2
Extremely Bright THz Radiation from Two-color Filamentation of Mid-infrared Laser Pulses
Vladimir Yu. Fedorov, Stelios Tzortzakis
Year: 2018, ISBN:978-1-943580-42-2
Impact of Polarization on Mid-IR Air Filaments
V. Shumakova, C. Gollner, A. Baltuška, V. Yu. Fedorov, S. Tzortzakis, A. Voronin, A.V. Mitrofanov, A.M. Zheltikov, D. Kartashov, A. Pugžlys
Year: 2018, ISBN:978-1-943580-42-2
Exceeding the bulk modification threshold of silicon with hyper-focused infrared femtosecond laser pulses
Margaux Chanal, Vladimir Yu Fedorov, Maxime Chambonneau, Raphaël Clady, Olivier Utéza, Stelios Tzortzakis, David Grojo
Year: 2017, ISBN:978-1-5090-6736-7
Sculptured ultrashort laser wave packets for advanced materials engineering
Stelios Tzortzakis
Year: 2017, ISBN:978-1-5090-6736-7
Strong power upscaling of THz sources based on laser filamentation in transparent media
A. D. Koulouklidis, I. Dey, C. Daskalaki, V. Yu. Fedorov, K. Jana, A. Mondal, M. Shaikh, D. Sarkar, A. D. Lad, G. R. Kumar, A. Couairon, S. Tzortzakis
Year: 2017, ISBN:978-1-5090-6736-7
Cavity ring-down spectroscopy for the isotope ratio measurement of methane in ambient air with DFB diode laser near 1.65 μm
A Bicer, J Bounds, F Zhu, AA Kolomenskii, S Tzortzakis, HA Schuessler
Year: 2017, ISBN:978-1-5090-6736-7
Enhancing THz radiation from two-color laser-induced air-plasma by using abruptly autofocusing beams
Kang Liu, A. D. Koulouklidis, D. G. Papazoglou, S. Tzortzakis, X.-C. Zhang
Year: 2016, ISBN:978-1-943580-19-4
Linear and nonlinear exotic light wave packets physics and applications
Stelios Tzortzakis
Year: 2015, ISBN:978-1-943580-03-3
Reconstruction of ultra-broadband THz electric field distorted by electooptic sampling
A. D. Koulouklidis, V. Yu. Fedorov, S. Tzortzakis
Year: 2015, ISBN:978-1-4673-7475-0
Two-color mid-infrared laser filaments produce terahertz pulses with extreme efficiency
Koulouklidis D. A. Gollner, C. Shumakova, V. Fedorov, V. Pugzlys, A. Baltuska, Tzortzakis S
Year: 2019, ISBN:978-1-7281-0469-0
Linear and nonlinear exotic light wave packets, physics and applications
G Dimitris Papazoglou, Stelios Tzortzakis
Year: 2022, ISBN:9781785612411


Prof. Tzortzakis Stelios
University Faculty Member

Scientific Staff

Prof. Papazoglou Dimitrios
University Faculty Member

Technical Staff

Mr. Loulakis Michael
Ms. Daskalaki Christina

Research Associates

Dr. Koulouklidis Anastasios
PostDoctoral Fellow
Dr. Fedorov Vladimir
PostDoctoral Fellow
Dr. Manousidaki Mary
PostDoctoral Fellow


Mr. Konstantakis Panagiotis
Ph.D. student


Ms. Lanara Christina
M.Sc. student