Laser evolution and plasma wave excitation by a relativistically intense short-pulse laser in underdense plasma are investigated in the broad pulse limit, including the effects of pulse steepening, frequency redshifting, and energy depletion. The nonlinear plasma wave phase velocity is shown to be significantly lower than the laser group velocity and further decreases as the pulse propagates ow...

ABSTRACT Multiple foci are created along the propagation direction of a laser beam using simultaneous spatial and temporal focusing of an ultrafast laser pulse in conjunction with parametric pulse shaping. The pulses are characterized with scanning SEA TADPOLE. The longitudinal and transverse positions of the foci are controlled using phase and amplitude shaping in a 4-f laser pulse shaping sys...

Measurement of stress transients generated by a 400ns pulsed HF laser in an infrared fluoride glass fiber has been made using fast time – response piezoelectric film transducer. Acoustic signals up to 12 mV with frequencies ranging in megahertz generated by 21 mJ laser pulse when passed through the fiber axis in the linear region. It is shown that useful information such as onset of non - linea...

A long air plasma channel can be formed by filamentation of intense femtosecond laser pulses. However, the lifetime of the plasma channel produced by a single femtosecond laser pulse is too short (only a few nanoseconds) for many potential applications based on the conductivity of the plasma channel. Therefore, prolonging the lifetime of the plasma channel is one of the key challenges in the re...

Akbari A1 1. Assistant Professor, Department of Physiotherapy, Faculty of Medicine, Zahedan University of Medical Sciences Abstract Background: Shoulder pain is the third most prevalent cause of musculoskeletal disorder after low back and cervical pains. Most of the shoulder symptoms are attributed to the rotator cuff. The objective of this study was to compare the effects of low-power ...

Copropagation of a laser pulse and a relativistic electron beam in a corrugated plasma channel has been proposed for the direct laser acceleration of electrons [Palastro, Phys. Rev. E 77, 036405 (2008)]. The corrugated plasma channel allows for the guiding of laser pulses composed of subluminal spatial harmonics. Phase matching between the electron beam and the spatial harmonics results in acce...

In this article, the thermoelastic interactions in an isotropic and homogeneous semi-infinite medium with variable thermal conductivity caused by an ultra-short pulsed laser heating based on the linear nonlocal theory of elasticity has been considered. We consider that the thermal conductivity of the material is dependent on the temperature. The surface of the surrounding plane of the medium is...

Introdouction: Dentinal hypersensitivity (DH) is one of the most painful chronic problems reported in dental offices. Various methods have been applied for the treatment of DH. However, majority of them are either ineffective or last for a short period of time. It has been reported that lasers, particularly Neodymium- doped: Yttrium Aluminum Garnet laser (Nd: YAG), can be helpful in the treatme...

a r t i c l e i n f o Keywords: Laser-induced breakdown spectroscopy Double pulse LIBS Laser ablation Laser heating Laser-induced particles Double-Pulse Laser-Induced Breakdown Spectroscopy of iron using both Nd:YAG and TEA–CO 2 lasers has been investigated to better understand mechanisms of signal enhancement. The signal dependence on the delay between the two laser pulses shows an enhanced si...

Absfrucf-A dynamic theory of semiconductor laser amplifiers is developed which takes into account the coherent time-dependent amplification of an incident optical pulse as well as the nonlinear dynamics of the semiconductor laser when driven by an unbiased injection current pulse. For suitable time delays between the optical and the electrical pulse, a strongly nonlinear self-induced shortening...