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A compact gain-switched all-fiber ytterbium laser operating at a wavelength of 1127 nm with the ability to control pulsed radiation parameters has been investigated. Gain switching was carried out by modulating the current of a semiconductor pump diode. With pumping energy ranging from 197.6 to 263.5 μJ, there was one generation pulse per each pump pulse with a duration of 0.43 to 1.1 μs, energy of 5.3 to 8.8 μJ, and a repetition rate of 100 Hz. Increasing the pumping energy above 265 μJ led to a change in the shape of generated pulses and to their energy rising up to 70 μJ. [ABSTRACT FROM AUTHOR]

All-fiber autocollimation schemes of the laser Doppler velocimeter (LDV) are presented that enable measuring velocities of hard-to-access objects in the range from several cm/s to several km/s. The autocollimation scheme covered in this work allows distant (several tens and hundreds of meters away) objects with the only working channel less than 5 mm in diameter to be investigated using a narrow laser beam. An acousto-optic modulator is used to modify Mach–Zehnder interferometer scheme to extend the range of measured velocities and allow distinguishing the motion direction. Air guns with the 4.5-mm-diameter bore have been used for test measurements. Velocities ranging from 0.1 to 330 m/s have been successfully measured. [ABSTRACT FROM AUTHOR]

Dual-frequency lasing is obtained in a disk laser with a two-mirror degenerate-type cavity and M-shaped configuration of an intracavity off-axis beam. Lasing occurred at two lowest-order transverse modes. Dual-frequency lasing has been realized due to spectral-selective properties of the cavity itself without using additional optical elements. The intermode beat frequency was 360 MHz, and the width of each spectral component did not exceed 1.5 kHz ( 5 × 10–8 cm–1). [ABSTRACT FROM AUTHOR]

We present here the results of clinical studies of the treatment of bedsores by activation of repair processes in integument tissues using pulsed cold plasma discharges in patients in a chronic critical state. An experimental device for radio-frequency current treatment is described and exposure specifications are presented. The mechanism of activation by cold plasma discharges in the tissue electrolyte matrix is described. The results reliably show that the action of radio-frequency current pulses with optimum parameters reduces the in-patient treatment period by an average of seven days, or by 16%, compared with the control group. [ABSTRACT FROM AUTHOR]

A prototype device for biological activation of aqueous solutions is presented. The activation is carried out using non-equilibrium (electrolyte) plasma generated by high-frequency glow discharge in water vapor at atmospheric pressure. The structure and functional features of the device are described. The results of investigation tests are presented, including the ranges of the main electrochemical parameters of activated aqueous solutions. It is shown that the activation of aqueous solutions with glow discharge electrolyte plasma is a low-cost procedure that can be implemented under laboratory or field conditions using a small-size device. [ABSTRACT FROM AUTHOR]

We present results from experimental studies supporting the use of electrolytic glow discharge plasma to destroy renal concretions. The rate of fragmentation of urinary stones was assessed in relation to the power of the plasma discharge and the duration of treatment. The process of plasmakinetic lithotripsy was found to be effective for fragmentation of different types of urinary stone. The results lead to the conclusion that plasmakinetic destruction of renal concretions is a fundamentally novel, effective, and economical method which combines well with technologies using radio-frequency surgery in saline for the treatment of pathological processes in urology. [ABSTRACT FROM AUTHOR]

We present results from experimental studies supporting the use of electrolytic glow discharge plasma to destroy renal concretions. The rate of fragmentation of urinary stones was assessed in relation to the power of the plasma discharge and the duration of treatment. The process of plasmakinetic lithotripsy was found to be effective for fragmentation of different types of urinary stone. The results lead to the conclusion that plasmakinetic destruction of renal concretions is a fundamentally novel, effective, and economical method which combines well with technologies using radio-frequency surgery in saline for the treatment of pathological processes in urology. [ABSTRACT FROM AUTHOR]

The all-fiber pulsed erbium laser with intracavity Mach–Zehnder modulator, operating in the Q-switching mode, is implemented. Stable modes of pulsed lasing at a wavelength of 1551 nm are demonstrated. The pulse repetition rate is varied in the range from 9.2 to 27.6 kHz. The pulse durations is varied in the range from 0.66 μs to 1.76 μs. Peak powers are varied in the range from 2.28 W to 0.76 W. [ABSTRACT FROM AUTHOR]

Efficiency of the transmission of high-frequency signals by semiconductor plasma antennas based on Ge and Si single crystals with surface nonequilibrium electron-hole plasma generated by laser diode radiation has been experimentally studied. Dependences of the amplitude of a radiated 6- to 7.5-GHz microwave signal on the laser power and size of the laser-irradiated region on the semiconductor transmitting dipole antenna are determined. It is shown that a more than tenfold increase can be achieved in the efficiency of useful signal transmission by the plasma antenna formed in Ge crystals. [ABSTRACT FROM AUTHOR]