The interaction of an ultraintense, 30-fs laser pulse with a preformed plasma was investigated as a method of producing a beam of high-energy electrons. We used thin foil targets that are exploded by the laser amplified spontaneous emission preceding the main pulse. Optical diagnostics show that the main pulse interacts with a plasma whose density is well below the critical density. By varying ...

A comprehensive model of ultrafast laser-induced plasma generation intended for coupling with pulse propagation simulations in transparent solids is introduced. It simultaneously accounts for the changing spectrum of a propagating ultrashort laser pulse while coupling to the evolution of the energy-resolved nonequilibrium free-carrier distribution. The presented results indicate that strong pul...

A highly enriched uranium coupled reactor consisting of pulse cores and a laser module is known as one of the reactors for nuclear-pumped laser. Neutronic analysis on a low enriched uranium coupled reactor which consists of pulse cores and a laser module was performed. Calculation results showed that a low enriched uranium coupled reactor could achieve criticality by using several expanded puls...

We have investigated the polarization of attosecond light pulses generated from relativistic few-cycle laser pulse interaction with the surface of overdense plasmas using particle-in-cell simulation. Under suitable conditions, a desired polarization state of the generated attosecond pulse can be achieved by controlling the polarization of the incident laser. In particular, an elliptically polar...

We demonstrate generation of sub-100 fs pulses at 1.5 µm in a mode-locked erbium-doped fiber laser using a 45°-tilted fiber grating element. The laser features a genuine all-fiber configuration. Based on the unique polarization properties of the 45°-tilted fiber grating, we managed to produce sub-100 fs laser pulses through proper dispersion management. To the best of our knowledge, this is the...

We demonstrate strong laser-field-free orientation of absolute-ground-state carbonyl sulfide molecules. The molecules are oriented by the combination of a 485-ps-long nonresonant laser pulse and a weak static electric field. The edges of the laser pulse create a coherent superposition of two rotational states resulting in revivals of strong transient molecular orientation after the laser pulse....

An overview on femtosecond laser pulse shaping techniques applied to control of the initial photo-physical steps involved in materials processing is presented. First, pulse shaping methodology in frequency domain is introduced and examples of shaped pulses relevant to laser microfabrication are discussed. Then, the use of tailored femtosecond pulses to control the initial steps of laser process...

The influence of self-phase modulation (SPM) and group-velocity dispersion (GVD) on pulse development in a passive mode-locked dye laser is investigated numerically by using fast Fourier transformations. The situation of positive SPM is considered. Four regions of laser performance may be distinguished: (i) In the positive GVD region pulse broadening by GVD must be balanced by the pulse-shorten...

We experimentally study the dynamics of the plasma induced by the double-laser-pulse irradiation of solid target in water, and find that an appropriate choice of the pulse energies and pulse interval results in the production of an unprecedentedly mild (low-density) plasma, the emission spectra of which are very narrow even without the time-gated detection. The optimum pulse interval and pulse ...

PURPOSE Retinal laser photocoagulation represents a major treatment strategy for the management of diabetic macular edema (DME). However, the thermal nature of this procedure defines that collateral tissue injury result, meaning that it cannot be used near the fovea centralis. We studied inflammatory and glial responses resulting from treatment of rats with a conventional laser and with a novel...