Time-resolved microscopy of femtosecond laser filaments in fused quartz

Kadan, Viktor
Blonskyi, Ivan
Pavlov, Ihor
Detailed picture of continuous shape evolution of femtosecond laser pulse has been recorded directly in the process of filament formation in fused silica using time-resolved polarization microscopy with similar to 70 fs temporal resolution. The main stages of the pulse transformation (temporal self-compression and splitting, formation of conical wave) have been studied. The maximum temporal compression has been found to be achieved by the leading subpulse after the time splitting event. It was found that the Bessel zone of conical wave formation is shifted backwards from the pulse front. Sub-and superluminal propagation velocities of the pulse maxima after the time splitting have been measured.


Quantitative atom-resolved force gradient imaging using noncontact atomic force microscopy
Oral, Ahmet; ÖZER, HAKAN ÖZGÜR; HOFFMANN, PM; PETHICA, JB (2001-09-17)
Quantitative force gradient images are obtained using a sub-angstrom amplitude, off-resonance lever oscillation method during scanning tunneling microscopy imaging. We report the direct observation of short-range bonds, and the measured short-range force interaction agrees well in magnitude and length scale with theoretical predictions for single bonds. Atomic resolution is shown to be associated with the presence of a prominent short-range contribution to the total force interaction. It is shown that the b...
Image formation model for photon sieves
Öktem, Sevinç Figen; Kamalabadi, Farzad (2013-09-15)
A photon sieve, modification of a Fresnel zone plate, has been recently proposed to achieve higher resolution imaging and spectroscopy at UV and x-ray wavelengths. In this paper, we present Fresnel imaging formulas that relate the output of a photon sieve imaging system to its input, originating from either a coherent or incoherent extended source. By using a well-known model for the zone plate, we also provide approximations to these imaging formulas, which are more efficient to compute. These imaging rela...
Local thermal resonance control of GaInP photonic crystal membrane cavities using ambient gas cooling
Sokolov, Sergei; LİAN, Jin; Yüce, Emre; COMBRİÉ, Sylvain; LEHOUCQ, Gaelle; De Rossi, Alfredo; Mosk, Allard P. (2015-04-27)
We perform spatially dependent tuning of a GaInP photonic crystal cavity using a continuous wave violet laser. Local tuning is obtained by laser heating of the photonic crystal membrane. The cavity resonance shift is measured for different pump positions and for two ambient gases: He and N-2. We find that the width of the temperature profile induced in the membrane depends strongly on the thermal conductivity of the ambient gas. For He gas, a narrow spatial width of the temperature profile of 2.8 mu m is pr...
Femtosecond filamentation in chalcogenide glasses limited by two-photon absorption
Blonskyi, Ivan; Kadan, Viktor; Shpotyuk, Oleh; Iovu, Mihail; Pavlov, Ihor (2010-09-01)
Filamentation of 800 nm femtosecond laser pulses in the conditions of strong two-photon absorption was first directly observed in As4Ge30S66 chalcogenide glass, this effect being accompanied by increase in the pulse spectrum width from 8.5 to 11 nm and its modulation indicating the pulse temporal splitting. In contrast, there was no filamentation and pulse spectrum widening in stoichiometric As2S3 glass. The nonlinear figure of merit was shown to be as high as 0.5 and only similar to 0.1 in glassy As4Ge30S6...
Real-time scanning hall probe microscopy
Oral, Ahmet; HENİNİ, M (1996-08-26)
We describe a low-noise scanning Hall probe microscope having unprecedented magnetic field sensitivity (similar to 2.9x10(-8) T/root Hz at 77 K), high spatial resolution, (similar to 0.85 mu m),nd operating in real-time (similar to 1 frame/s) for studying flux profiles at surfaces. A submicron Hall probe manufactured in a GaAs/A1GaAs two-dimensional electron gas (2DEG) is scanned over the sample to measure the surface magnetic fields using conventional scanning tunneling microscopy positioning techniques. F...
Citation Formats
V. Kadan, I. Blonskyi, and I. Pavlov, “Time-resolved microscopy of femtosecond laser filaments in fused quartz,” OPTICS COMMUNICATIONS, vol. 505, pp. 0–0, 2022, Accessed: 00, 2022. [Online]. Available: https://hdl.handle.net/11511/95147.