We experimentally demonstrate an efficient way to control and stabilize single optical filaments initiated by ultrashort laser pulses in a rare gas medium. This is done by the application of a stationary two-dimensional phase mask to the laser beam prior to focusing. Simple circular phase-step patterns of a given radius and relative phase are sufficient to stabilize the pointing of the filament...

Simultaneous spatial and temporal focusing (SSTF) of femtosecond laser pulses gives rise to strong suppression of nonlinear self-focusing during the propagation of the femtosecond laser beam. In this paper, we begin with an introduction of the principle of SSTF, followed by a review of our recent experimental results on the characterization and application of the spatiotemporally focused pulses...

Jones matrix computation is one of the widely used methods in nonlinearitycalculation in laser interferometers. In this paper, the nonlinearity error in developedthree-longitudinal mode heterodyne interferometer (DTLMI) has been mathematicallymodeled at various speeds, by using Jones matrix calculations. This review has been donedespite the fact that simultaneously the main factors including no...

laser is one of the sources that induce a biological effect in higher plants. the positive effect of laser on some crops has been proved. this research was carried out to study the effect of laser radiation on the accumulation of proline in spring wheat (triticum aestivum cv. kavir) under different nacl treatment levels. semi-coherent red beam, infrared beam and one-second harmonics of neodymiu...

In the last few years impressive advances in the development of high-power diode lasers (HPDL ́s) and their production technology have been achieved /1/. Output powers in the range up to 120 W out of one 10 mm diode laser bar have been reported /2,8/ as well as rapidly declining prices. In the past most activities concerning application of HPDL ́s have been focused on the pumping of solid-state l...

We apply well known nonlinear diffraction theory governing focusing of a powerful light beam of arbitrary shape in medium with Kerr nonlinearity to the analysis of femtosecond (fs) laser processing of dielectric in sub-critical (input power less than the critical power of self-focusing) regime. Simple analytical expressions are derived for the input beam power and spatial focusing parameter (nu...

LLE Review, Volume 91 103 Introduction The OMEGA facility is LLE’s 60-beam, 30-kJ (UV) laser system for performing inertial confinement fusion (ICF) experiments. One of the main features of the OMEGA laser is a flexible optical pulse–shaping system1 that produces 0.1to 5-ns, complex-shaped, low-energy pulses that must be amplified to ~1-mJ level before being injected into power amplifiers. Rege...

Study of the beam propagation behavior through oceanic media is a challenging subject. In this paper, based on generalized Collins integral, the mean irradiance profile of Gaussian laser beam propagation through ocean is investigated. Power In Special Bucket (PIB) is calculated. Using analytical expressions and calculating seawater transmission, the effects of absorption and scattering on beam ...

A laser-isotope-separation study of lithium has been performed with two-step excitation involving UV laser radiation and a visible tunable-diode laser. The method yields a high degree of selectivity by tuning the narrow-linewidth diode laser to the D1 or D2 levels of the lithium atom. Selective laser excitation is simplified by the use of the tunable diode laser and the overall approach benefit...