The paper presents a new approach for radiation mode formation, based on the proper choice of the discharge electrode's shape and the distance from the resonator's mirrors to the butt-end of electrodes. In theory and in experiment was shown the possibility to select the basic waveguide mode of radiation. For 2.5 KW slab CO2 laser, excited at 40,68MHz, was obtained the near diffraction-limited divergence.
The paper presents the new concept for radiation mode selection, based on the spatial filter system, which disposed on the electrode surface of slab CO2 laser. The results of the computer simulation and the experiment are discussed.
For the various pumping rates and for the various heights of the gap were calculated the average value of the small- signal gain and its profile across the gap. For the high power slab CO2-lasers, RF-excited at 40.68 MHz, were analyzed the ranges of their geometry parameters vibration, providing for the possibility of diffraction limited performance. In theory and in experiment was shown the possibility to select the basic waveguide mode of radiation.
The paper presents the results of measuring of the small-signal gain in the active medium of the high-power pulserepetitive RF-excited slab C02-laser. The measurements were carried out for the pumping pulse durations in the range 20.50 Ls and pulse repetition rates 100.500 Hz. The maximal specific energy, delivered to the active medium, was 430 W/cm3. In the experiment were measured the average output power of radiation, pulse energy and power and the output beam divergence.
The compact sealed-off RF-self-excited slab CO2 laser has been developed. The average output power in pulse- repetitive mode of operation is controlled in the range of 20 - 200 W. The maximum pulsed power exceeds 400 W. The divergence of laser radiation is close to diffraction limit. The weight of the laser-head and RF-power supply is in total 40 kg.
Slab RF-excited pulsed CO2-laser with the pumping frequency F equals 152 MHz, pulse duration in the range of 20 divided by 50 microsecond(s) , and pulse repetition rate f up to 100 Hz has been investigated. Output power, temporal shape of laser pulses, laser beam divergence were measured at the pumping power up to 400 W/cm3. Pulsed output power was varied in the range of 2 divided by 5 kW. The package of numerical simulation codes of pulse-repetition mode of slab CO2 laser was created. It is shown that the maximum input power is significantly increased by the change of excitation frequency from 80 up to 150 MHz. The measured and numerical data are compared.
Research and development of pulsed-repetitively slab rf- excited carbon-dioxide laser is presented. The experiments were carried out for two modes operation: meander mode (duty factor delta equals 50%) and pulse repetition mode at delta equals 12.5%. The range of 240 divided by 4000 Hz of pulse repetition frequency was used. Pulse power about 400 W for meander mode and up to 700 W for the second mode have been obtained. Input power, radiation pulse shape and output beam divergence were measured.
Results of experimental investigations of output power and beam divergence for a slab waveguide rf-excited carbon- dioxide laser are presented. Laser output power 150 - 250 W and maximum efficiency 10 - 13% in a beam with near- diffraction-limit divergence has been achieved. In repetitive-rate mode, the pulsed power was more than twice as much as the average one in the cw mode. After beam shaping lens, the sum beam divergence of 2.5 mrad at the 0.8 total power level has been obtained.
Results of investigations of a slab waveguide rf-excited carbon-dioxide laser are presented. Laser output power of range 200 W and efficiency about 10% in a beam with near-diffraction- limit divergence has been achieved. In the repetitive-rate mode, the pulsed power was more than twice as much as the average one in the cw mode. After beam shaping telescope, the total beam divergence of 2 - 3 mrad at the 0.8 power level has been obtained. A codes package of computer simulation of cw slab rf-excited diffusion-cooled carbon-dioxide laser was created. Comparison of calculated and experimental data has been fulfilled.
Results of investigations of output power and beam divergence for a slab waveguide rf-excited carbon-dioxide laser are presented. Laser output of range 200 W and efficiency about 10% in a beam with near-diffraction-limit divergence has been achieved. In the repetitive-rate mode, the pulsed power was more than twice as much as the average one in the cw mode. After beam shaping telescope, the total beam divergence of 2-3 mrad at the 0.8 power level has been obtained.
A codes package of computer simulation of rf-excited cw slab carbon-dioxide laser with diffusion-cooling and hybrid waveguide-unstable resonator is presented. The package consists of four main parts: (1) structure of rf-discharge, (2) processes of inversion formation, (3) laser radiation propagation throughout the resonator, and (4) plasma chemical reactions in the active medium. The calculations of gain, output power, and near- and far-field patterns have been carried out. Comparison of calculated and experimental data has been fulfilled.
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