N. A. Yudin

The possibilities of a strontium vapor laser using for laser sensing of minor gaseous components of the atmosphere

The present work studies the possibility of application of the multiwavelength laser on SrI and SrII self-terminated transitions for laser remote sensing of minor gaseous components (MGC) and meteorological parameters of the atmosphere using the differential absorption lidar (DIAL) method.

Thermal Cleavage of Optical Glass by Strontium-Vapor Laser Radiation

Controlled thermal cleavage of optical glass by strontium-vapor laser radiation was studied. It was shown that high-quality complete separation of display glass is determined by the multiwave spectrum of the absorbed radiation. Sr-Laser radiation (λ = 6.45 μm) absorbed in a about 200 μm thick ‘top’ layer forms a surface microcrack, just as in the case of CO2 laser radiation (10.6 μm). Radiation in the about 1 and 3 μm range forms a ‘volume’ microcrack. Together these cracks create an additional effect making it possible to increase in the periodic-pulse regime the rate and quality of the laser separation of optical glass at comparatively low average lasing power.

On the Mechanism of Limitation of the Frequency-Energy Characteristics of Metal Vapor Lasers

Electrophysical processes in the discharge circuit of a pulsed metal vapor laser are analyzed. The greatest attention is paid to the initial period of the discharge development and conditions for the inversion formation. It is shown that the limitation of the frequency-energy characteristics (FEC) of lasing is due to the process of populating the metastable levels of metal atoms on the excitation pulse front and redistribution of the rates of population of the laser levels in favor of metastable ones with an increase in the prepulse electron density. Which of the processes plays a decisive role in limitation of the lasing FEC depends on the electrophysical process in the discharge circuit of the laser, the development of which is significantly influenced by the arrangement of electrodes in the gas-discharge tube (GDT). The arrangement of electrodes in the GDT also determines the conditions for the inversion formation and the choice of the optimal pumping parameters. Technical solutions are discussed under which the pumping efficiency of a copper-vapor laser attains ~10%.

Application of a strontium vapor laser to laser remote sounding of atmospheric composition

The applicability of a method using a multiwave SrI and SrII self-contained laser to laser remote sounding by DIAL (differential absorption lidar) of the gas components and the meteorological parameters of the atmosphere are studied. The informative wavelengths for trace gas sounding are identified and attenuation of the gas components are measured.

Development of a strontium vapor laser with pulse repetition frequency up to 1 MHz

The problem of obtaining high pulse repetition frequencies in metal vapor lasers is urgent from the viewpoint of laser application to various technologies, increase of productivity of industrial laser systems, study of transient processes, etc. In addition, the high pulse repetition frequency provides large average laser radiation power in spite of a rather low energy extracted from a single lasing pulse. In this work, the possibility of increasing the pulse repetition frequency of a laser on self-terminated strontium ion transitions was investigated. The double pulse method was used to demonstrate experimentally that a pulse repetition frequency of ~1 MHz could be achieved at wavelengths of 1.03 and 1.09 μm of the strontium vapor laser. To explain the results obtained, the kinetics of the active medium was modeled using the self-consistent mathematical model of a He- Sr+ laser.

Promising technological and medical applications of strontium vapor lasers

In the Laboratory of Laser and Crystal Physics of Tomsk State University, the laboratory model of a multiplewavelength strontium vapor laser (SVL) with output power of 5-7 W was developed and manufactured, a number of investigations aimed at an increase in the output characteristics of this laser were performed, and a record energy characteristics were achieved, including total lasing power of 13.5 W, lasing power at two wavelengths in the region of 3 μm of 4.5 W, and lasing power at two wavelengths in the region of 1 μm of 1.9 W. A maximum total energy per lasing pulse reached 1.26 mJ for pulse repetition frequency of 8.6 kHz. Investigations were performed aimed at visualization of IR radiation of the strontium vapor laser by the violet recombination line of the strontium ion at λ = 0.4305 μm. These investigations indicated the possibility of developing a high-power strontium vapor laser with high lasing efficiency, wide range of variations of pulse repetition frequencies, and simultaneous multi-wavelength generation. In the present work, a number of applications of the multi-wavelength strontium vapor laser are considered in detail, including precision controlled laser thermal cleavage of fragile nonmetallic materials (glass thermo-optical space radiators, display screens, and chips on a sapphire substrate), and infrared laser resonant ablation (microsurgery and polymer treatment). In addition to the above-listed technologies, laser systems based on compact strontium vapor lasers can be used successfully for atmospheric sensing and gas analysis.