Characteristics of laser produced Cu plasma were investigated using spectroscopy, a CCD camera, and a Langmuir single probe. A pulsed Nd : YAG laser of 52 mJ, 335 nm, and pulse duration 7 ns was used for generating high density plasma in vacuum and argon buffer gas. Spectroscopic measurements were devoted to determine plasma lifetime, electron temperature T e , plasma velocity V p , and electron density N e . T e was determined using a Boltzmann plot and N e was determined using Stark line broadening. Langmuir single probe was located at 3.5 mm from Cu target to measure T e and N e . The T e values of the probe were coincident with the spatial profile of determined by spectroscopic measurements. Plasma lifetime and the CCD camera image were dependent on the Ar pressure. These plasma parameters improve the laser plasma deposition thin films.

A theoretical investigation is made into the ionisation of helium, at pressures of 1800-17000 Torr (0.24-2.27 MPa) by ruby laser radiation of pulse-length 40 ns. It is shown that, when the variation of electron energy gain in elastic collisions is taken into account, the agreement between computed and experimental breakdown threshold intensities is improved by a factor of 10 compared with calculations in which only the mean energy gain is computed. The agreement is also improved significantly by incorporating the collisional and multiphoton ionisation of excited helium atoms.

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Considers the simultaneous effect of the processes of multiphoton and cascade ionisation in producing ionisation and breakdown molecular gases under the influence of three different short-flash lasers of wavelengths 0.6943 mu m, 1.06 mu m and 0.53 mu m with pulse durations 18 ps, 7 ps and 25 ps respectively. The gas was studied over a pressure range of 1-105 Torr. The results of this work can be used to interpret experiments on breakdown of molecular gases by short duration laser pulses of ruby and Nd3+ lasers.