Shapes of self-broadened argon lines 687.1 nm (4d_{5}-2p_{10}), 703.0 nm (3s_{5}-2p_{9}), 750.3 nm (2p_{1}-1s_{2}) as well as the neon line 748.8 nm (3d_{3}-2p_{10}) emitted from glow discharges at low pressures were analysed using a Fabry Perot interferometer. We showed that the dissociative recombination of Ar^{+}_{2} (or Ne^{+}_{2}) molecular ions which gives rise to the density of non-thermalized atoms, may be regarded as the main process responsible for the distortion of the profiles of the above lines. The distorted profiles were analysed as superposition of the Ballik profile for thermalized atoms and the modified Ballik profile for non-thermalized atoms. The Lorentzian and Gaussian widths as well as relative densities of non-thermalized and thermalized atoms were determined.
The second-order differential equation for the asymmetric Voigt profile is presented, leading to a powerful and accurate method of determining the line shape parameters.
A detailed analysis of the deviations from the Voigt profile caused by the correlation effects and collision-time asymmetry observed by means of a Fabry-P'erot interferometer is presented. An expression for the response of scanning Fabry-P'erot interferometer to the speed-dependent asymmetric Voigt profile is derived.
Using an interferometric method, detailed analysis of the line shapes of the self-broadened 748.8 nm Ne line emitted from the glow discharge at low pressure of neon was performed in wide temperature range. Systematic departures from the ordinary Voigt profile were observed. We have shown that the dissociative recombination of molecular Ne^{+}_2 ions which gives rise to the non-thermalized neon atoms may be regarded as the main process responsible for the distortion of the profile of the investigated line.
The collision-time asymmetry coefficients as well as the pressure broadening and shifting rates of the ^{114}Cd 326.1 nm line perturbed by noble gases are calculated in the framework of the non-adiabatic semi-classical method using the Czuchaj et al. potentials. The theoretical values are compared with experimental results determined recently by means of laser-induced fluorescence technique.
The experimental values of pressure broadening and shift coefficients of the ^{114}Cd 326.1 nm line perturbed by H_{2} and D_{2} are determined using a LIF technique and compared with theoretical values calculated from the impact theory.
Profiles of the self-broadened 748.8 nm Ne line emitted from a glow discharge in neon in the pressure range between 0.8 and 100 Tr were measured using an improved experimental setup with pressure-scanned Fabry-Perot interferometer. First, line profiles were analysed using an ordinary Voigt procedure which yielded the Doppler widths decreasing with the increase in neon pressure. Using a speed-dependent Voigt profile it was shown that for the 748.8 nm line the correlation between the Doppler and collisional broadening plays an important role. However, the values of the pressure broadening and shift coefficients determined by the speed-dependent Voigt analysis were found to be only slightly different from those obtained by the ordinary Voigt analysis. A systematic error in the determination of perturber concentration in our previous investigation was corrected.
The profiles of argon perturbed components of the 5^{1}S_0-5^{3}P_1 line of the even-odd ^{113}Cd isotope were measured using a laser-induced fluorescence method. It was shown that the asymmetries of the profiles are due to both the collision-duration and line-mixing effects.
We present ultra-narrow line width, tunable diode laser system which will be used as a local oscillator in an optical atomic clock and for precision spectroscopy of Sr near 689 nm. Design of the high finesse optical cavity used as short-term frequency reference is optimized with respect to insensitivity to vibrations. We achieved laser line width of about 8 Hz, measured by comparison of two identical systems. The relative phase lock of two lasers is better than 150 mHz. Laser tunability and usefulness for precison spectroscopy were demonstrated through line shape measurement of a 20 kHz wide resonance of the optical cavity.