[en] The technique of laser-induced breakdown spectroscopy (LIBS) has become an established technique for rapid spot analysis of solid samples. Since laser is used to vaporize the sample, little or no preparation is required and trace elements can be detected in the bulk and as surface contaminants. In this paper, the physicals characteristics and instrumentation which are of importance for quantitative investigations, are described. These include the determination of the concentration of alloy constituents, the detection of surface contaminants and the use of measured line intensities to calculate electron temperatures in laser produced plasmas. Representative examples for a number of targets are given

No abstract available

No abstract available

[en] To learn how to take matter apart atom-by-atom and to count each atom according to its type, regardless of its initial chemical or physical state, is presumably a worthy goal in scientific research. The advent of the laser created real hope that these aspirations will be realized. The counting of atoms is not merely an intellectual exercise set apart from real-world applications. On the contrary, even though the capability is scarcely more than five years old, practical applications have been made in many fields of chemistry, physics, the environment, and industry. In this lecture we wish to review how the laser made possible the counting of atoms and how this capability has been put to use in situations where atoms are free to react chemically as they diffuse through a medium. Fluctuation phenomena and statistical mechanics can also be examined in these situations

[en] Short communication

[en] Such well-known techniques as radiation echo, the method of quantum beats, and superradiance are widely used in studying relaxation processes both in gases and in condensed media. These techniques are based on coherent processes. The advent of lasers extended extremely the potentialities of these methods in the optical band. Over the last years new spectroscopic methods were developed in optics on the basis of narrow nonlinear optical resonances. The methods proved to be very useful in examining low-pressure gases as they permitted obtaining Doppler free resonances with a homogeneous width. This increased to a great extent a spectroscopic resolution in the optical band and simultaneously permitted studies into relaxation phenomena. A lot of methods to obtain Doppler free narrow resonances have been developed in optics by now. The following methods are widely used in nonlinear laser spectroscopy: 1) Method of saturated absorption. 2) Two-photon resonances. 3) Saturation resonances of stimulated Raman scattering. 4) Method of separated optical fields. (orig./WL)

[en] The investigations of currency coins dated back to many centuries. Many researchers developed an interest in the investigation of the coin’s weight, size, physical feature and elemental composition. Laser-induced breakdown spectroscopy (LIBS) has the novelty of analytical analyses of various samples. It has the ability for the elemental composition determination of samples of solid (including metals), liquid and/or gases. Malaysia as a country uses Ringgit as a currency, among which are coins of 10, 20 and 50 cents. These coins are in series of release from the Malaysian Central Bank from time to time. There are currently in circulation old and new coins of 5, 10, 20 and 50 cents coins. These coins differ in their physical features and are may be different also in their elemental composition. This paper presents the investigation of the differences in elemental composition between the old and new Malaysian coins of 10, 20 and 50 cents. Principal component analysis (PCA) was used to perform the discrimination between the coins from the LIBS spectra. (paper)

[en] The thermal response of filters required in laser spectroscopy is discussed. Bandpass and neutral density filters produce transiently oscillating beam intensities when expanded to moderatley intense laser beams. It is stressed that careful placement of filters is needed to avoid these oscillating phenomena and the resulting inaccuracies

[en] The manner in which laser spectroscopic techniques can be use to probe collisional processes in atomic vapors is reviewed. A discussion of the saturation spectroscopy of three-level systems, coherent transient spectroscopy, and a beam-laser spectroscopy system is presented. It is shown that such experiments can provide useful information on both the total and differential cross sections for atom-atom scattering

[en] The authors report new far-infrared laser lines generated from two fully deuterated isotopomers of methanol:¹2CD₃OD and ¹3CD₃OD; five from ¹2CD₃OD and 22 from ¹3CD₃OD, which added to the previously reported far-infrared laser lines in these two molecules sums up to 300. The laser lines were mainly pumped by the 10R (regular) and 10SR (sequence) bands of a cw-CO² laser. The authors measured their frequencies, relative intensities, relative polarizations and pump offsets. The laser lines are in the spectral range from 43.697 to 719.426 μm (6860 664.6 to 416 710.4 MHz)