Radiation properties of the arrays of linear lasers optically coupled with a spatial filter method and of the system consisting of two ring lasers with unidirectional generation and one-sided optical coupling are studied.
Experimental investigations of radiation parameters of 2D arrays of waveguide CO2 lasers synchronized by in-cavity spatial filter method are carried out. Phase locked regime in a system of two ring waveguide CO2 lasers with a common cavity and unidirectional lazing was achieved and investigated.
Under conditions of mutual coherence of the amplified laser beams the power and axial brightness amplification for the two-channel version of the amplifier are experimentally measured. Numerical investigations of the amplifier radiation characteristics are carried out including a random spread of the parameters of separate channels both for the two-channel and multichannel amplifier.
A report is given of the construction of a high-power (P approximately 1 kW) multibeam cw CO2 laser, with diffusive cooling of the gas mixture and excited by a 10 kHz ac discharge. The design of the laser is described and experimental measurements of its basic characteristics presented. These included measurements of the laser divergence and an investigation of the influence of the pressure, composition, and circulation velocity of the gas mixture on the laser output power. The experimental data obtained and a comparison of the parameters with those of other known lasers are used to discuss its advantages and prospects for use in technological applications are discussed.
We report the development of a multibeam laser, excited by an ac discharge in the frequency range approximately 10 to 70 kHz. The results are given of an investigation of the active medium and of the dependence of the output characteristics of such lasers on the discharge tube diameter, pressure in the gas mixture, and frequency of the pumping current.
A high-power waveguide CO2 amplifier with injection locking was constructed. Its energy and frequency characteristics were investigated. Single-frequency radiation of 50 W power was generated under quasi-cw operation conditions.
A study was made of the influence of misalignment of the plane mirrors of a waveguide CO2 laser on the output power and mode structure of the radiation. It was found that misalignment of the resonator only weakly affected the output power, but exerted a strong influence on the beam divergence and maximum radiation intensity in the far-field zone. A qualitative agreement was obtained between the experimental results and the proposed theoretical model.
An experimental investigation was made of the operating regimes of a pulse-periodic waveguide CO2 laser employing diffusive gas cooling and excited by a longitudinal 10 kHz ac capacitative discharge. A specific average radiation output power of 12 W/m was obtained at repetition frequencies of 1 kHz and feasibility of control of the shape of the lasing pulse was demonstrated. The results of these experiments can be used to construct multibeam pulse-periodic CO2 lasers for heat processing.
Interest has recently turned to multibeam CO waveguide lasers1'2 as simple, compact sources of intense infrared light. A multibeam laser is an array of parallel discharge tubes (elements) between common plane mirrors. When the elements of the multibeam laser generate light independently, the intensities of all the beams are summed in the far zone (in the focusing plane), and the size of the focus is determined by the divergence of the beam from an individual element and the overall aperture of the multibeam laser. This circumstance imposes an upper limit on the light intensity at the focus. Another consequence of the independent operation of the elements of a random distribution of the light spectrum and polarization over the output aperture. This random distribution in turn has the consequence that it is not possible to realize the full potential of "focusators,t' which are optical devices of a new type for producing a given intensity distribution in a focus3 There is accordingly considerable interest in operating the various elements coherently, so that the multibeam laser operates as a single spatially coherent source. In this case the far- zone light intensity distribution is the result of an interference of all the beams. According to estimates in Ref. 4, operating all the elements of the multibeam laser of Ref. 2 coherently wifi lead to a maximum light intensity in the far zone about 50 times as high as during independent operation of the elements. It has also been shown that a coherent array of waveguide CO lasers can be used for L1DAR4 to produce short light pulses with a high repetition frequency.4'6 Phase locking of the elements of a multibeam laser will therefore substantially extend the possible range of applications and, in particular, permit an increase in the light intensity at the focus.
Bifurcation and chaotic lasing regimes have been observed for the first time ever in a system of optically coupled CO2 lasers. The regions of stable laser mode locking are determined analytically and numerically. The dynamic regimes in the absence of mode locking are calculated. Agreement between experimental and numerical results is obtained.
It is predicted theoretically and verified experimentally that an effective phase-locking of a two-dimensional array of lasers can be achieved by making use of the reproduction of the wave front of a periodic structure of coherent radiators.
A determination was made of the dependencies of the small-signal gain, saturation power, and gas temperature on the discharge tube diameter, working pressure, and discharge current in a wave-guide CO2 laser excited by a longitudinal alternating-current (5 - 100 kHz) capacitance discharge. The results established that the scaling laws were applicable and a comparison was made of the efficiency of this excitation method with other methods.
The modern state and perspectives of development of high power multibeam CO2 lasers are described. The problems of phase locking of laser arrays and main lobe energy maintenance increase are discussed also.
This paper is a review of experimental and theoretical results obtained at Kurchatov Atomic Energy Institute. The paper reviews the possibility of developing high-power laser systems on a base of coupled CO2 laser arrays.
The experimental and theoretical investigations of radiation dynamic in a system of two optically-coupled C02-lasers and in a periodically - pumped COlaser are carried out. In a optically-coupled lasers on the edge of theirs locke- band and in a periodically-pumped laser near threshold the transition of lasers to the chaotic generation through subsequent period-doubling bifurcations are experimentally revealed. A good agreement between experimental and theoretical results was obtained.
This paper is a review of experimental and theoretical results obtained at Branch of Kurchatov's Atomic Energy Institute to understand the possibility of development of high power laser systems on base of coupled C02 laser arrays.
The results of experimental and theoretical investigations of the different methods of phase locking of an array of lasers, the selection one supermode and the increasing of energy in mane maximum of focal spot are described. The practical realization of this methods opens the real perspectives to improve the brightness of radiation of multibeain CO2 lasers and to expand the area of there application in the thermal technology.