Blonskyi, I.
Kadan, V. M.
Pavlova, S.
Pavlov, Ihor
Shpotyuk, O.
Khasanov, O. K.
The peculiarities of the femtosecond filamentation in Kerr media has been studied using a set of time-resoling experimental techniques. These include the temporal self-compression of a laser pulse in the filamentation mode, repulsive and attractive interactions of filaments, and influence of the birefringence on the filamentation. The propagation of femtosecond laser pulses at the 1550-nm wavelength in c-Si is studied for the first time using methods of time-resolved transmission microscopy. The nonlinear widening of the pulse spectrum due to the Kerr- and plasma-caused self-phase modulation is recorded.


Surface Enhanced Raman Spectroscopy of the plasmonic nanogratings obtained by Laser Induced Periodic Surface Structuring
Erkızan, Serena Nur; Bek, Alpan; Department of Physics (2023-1-31)
The research conducted in this study presents a novel method of generating highly sensitive Surface Enhanced Raman Spectroscopy (SERS) substrates by femtosecond laser writing techniques. Two different types of periodicity regimes are introduced by femtosecond laser-based nano-structuring of crystalline Silicon (Si) and generated patterns are classified as Low Spatial Frequency LIPSS (LSFL) and High Spatial Frequency LIPSS (HSFL). Quasi periodic, self-organized femtosecond laser written periodic nanostructur...
Pulsed optically stimulated luminescence from α-Al2O3:C using green light emitting diodes
Bulur, Enver (1997-01-01)
Optically Stimulated Luminescence (OSL) from alpha-Al2O3:C was investigated using green light emitting diodes (LED) for excitation. Time resolved luminescence characteristics of the samples were studied by pulsing the LEDs during the readout. The effects of excitation light intensity, pulse width and readout temperature on the OSL signal were investigated. The radiation dose response of the dosimeters with above mentioned parameters was also evaluated for the applicability to radiation dosimetry.
Polycrystalline plasticity modeling of anisotropic grain structures and statistical size effect in metallic alloys
Orhun, Bulut; Yalçınkaya, Tuncay; Department of Aerospace Engineering (2022-6-14)
In this thesis, two important microstructural phenomena affecting the plastic behavior of metallic materials are addressed through a local crystal plasticity modeling framework. Initially the influence of anisotropic grain structure developing during various forming procedures and additive manufacturing processes is studied following a multiscale modeling strategy, where Representative Volume Elements (RVEs) are analyzed under axial loading conditions. Macroscopic response of different degrees of anisotropi...
Space-charge-limited current analysis in amorphous InSe thin films
Yılmaz, Koray Kamil; Parlak, Mehmet (2004-04-01)
The study of space-charge-limited currents (SCLC) in amorphous InSe thin films is presented. The temperature-dependent current-voltage (J-V) measurements were carried out for TO/a-lnSe/Au sandwich structures in the range of 200-320 K. For all samples, ohmic behavior was observed up to an electric field strength of about 2 x 10(5) V cm(-1). From the temperature dependence of conductivity data, the position of the thermal equilibrium Fermi level E-fo is determined as 250 meV above the valence band E-v. At hig...
Experimental characterization of a tuned vibration absorber
Aksoy, Tuğrul; Özgen, Gökhan Osman; Acar, Bülent; Gençoğlu, Caner (2016-01-01)
In this paper, experimental characterization studies conducted for a tuned vibration absorber is presented. The tuned vibration absorber has been particularly designed to reduce transverse resonant vibration response of a supported cylinder structure at its dominant two modes. Various testing configurations and techniques have been used such as transmissibility measurements, frequency response measurements, sweep sine testing, impact testing, and random testing. Different testing approaches were needed to e...
Citation Formats
I. Blonskyi, V. M. Kadan, S. Pavlova, I. Pavlov, O. Shpotyuk, and O. K. Khasanov, “ULTRASHORT LIGHT PULSES IN TRANSPARENT SOLIDS: PROPAGATION PECULIARITIES AND PRACTICAL APPLICATIONS,” UKRAINIAN JOURNAL OF PHYSICS, pp. 457–463, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57397.