FLASSS (Femtosecond Laser Spectroscopy in Solid State)

The FLASS laboratory is a unique laboratory for the Greek research community based on an amplified laser which delivers pulses at 1 kHz repetition rate, central wavelength at 785 nm, with maximum energy per pulse 0.8 mJ and 25 fs minimum pulse duration. Secondary optical sources include (Non-)Collinear Optical Parametric Amplifiers which provide a broad range of emission wavelengths spanning from the near UV to the near IR (~ 250 – 1500 nm). Additionally, a Spatial Light Modulator in a 4f optical correlator is used to modulate the temporal shape of the laser pulses in a temporal window extending to 14 ps. A pump-probe workstation equipped with the proper analysis instruments (spectrometer, monochromator, CCD imaging camera, lock-in amplifier etc.) allows for state-of the art pump-probe time-resolved all-optical spectroscopy at a variety of condensed matter systems. Future upgrades include a cryostat that will enable liquid He temperature measurements. A second workstation involves irradiation of solid surfaces (semiconductors, metals, dielectrics) with spatio-temporally shaped pulses with controllable polarization aiming to (i) study the ultrafast processes occurring during surface micro-/nanostructuring (ii) control and tune the surface nanostructures for applications. This workstation is dual-purpose: (a) direct surface irradiation and (b) surface nanostructuring via Laser-Induced Forward Transfer (LIFT).

Tzianaki, E. and Bakarezos, M. and Tsibidis, G. D. and Petrakis, S. and Loukakos, P. A. and Kosmidis, C. and Tatarakis, M. and Papadogiannis, N. A., “Controlling nanoscale acoustic strains in silicon using chirped femtosecond laser pulses”, Applied Physics Letters, 108, 254102 (2016), DOI:http://dx.doi.org/10.1063/1.4954636

N. Liaros, S. Couris, E. Koudoumas, and P. A. Loukakos, “Ultrafast Processes in Graphene Oxide during Femtosecond Laser Excitation” The Journal of Physical Chemistry C 2016 120 (7), 4104-4111,DOI: 10.1021/acs.jpcc.5b11943

Eirini Tzianaki, Makis Bakarezos, George D. Tsibidis, Yannis Orphanos, Panagiotis A. Loukakos, Constantine Kosmidis, Panos Patsalas, Michael Tatarakis, and Nektarios A. Papadogiannis, “High acoustic strains in Si through ultrafast laser excitation of Ti thin-film transducers,” Opt. Express 23, 17191-17204 (2015) doi: 10.1364/OE.23.017191

Barmina, E.V., Fotakis, C., Loukakos, P.A. Stratakis,  E., Shafeev, G.A., “Laser-assisted nanostructuring of Silicon in liquid environment” Appl. Phys. A (2014) 117: 359. doi:10.1007/s00339-014-8437-9

Tsibidis, G.D., Stratakis, E., Loukakos, P.A., Fotakis, C., “Controlled ultrashort-pulse laser-induced ripple formation on semiconductors” Appl. Phys. A (2014) 114: 57. doi:10.1007/s00339-013-8113-5

Foundation for Research and Technology - Hellas, Heraklion, Greece