Abstract: In order of maintaining at the more constant level the CO.sub.2 content in the gaseous mixture discharge of a transversely excited atmospheric pressure laser, a polymer product is included in advance of the laser operation in the laser chamber or within the closed fluidtight circuit where the gaseous mixture is recycled. Such polymer is produced by irradiating tripropylamine with ultraviolet photons and/or with energy electrons in the form of a layer whereby at least a portion of a solid support is coated.

Abstract: A gas operated laser is disclosed which comprises two main electrodes facing each other and connected with a single feeding capacitor both for the preionization and for the main laser discharge, wherein the gas preionization in the laser vessel is obtained by a corona discharge generator comprising a dielectric tube along the outside of which a conducting wire is stretched to contact the outer surface of the tube which conductor connects with one of the discharge electrodes while a thin conducting rod inserted in said tube connects with the other discharge electrode. As a first alternative an edge of a conducting material shape is used as a substitute for said conducting wire. As a second alternative the side sharp edge of one of the main electrodes is used in lieu of said conducting wire.

Abstract: A sealed structure laser apparatus is disclosed which utilizes corona discharge as a pre-ionizing means wherein the laser discharge space is defined by a dielectric material channel with C cross section and one of the two discharge main electrodes is located along the inner wall of the C channel opposite the C aperture while the other electrode confronts said aperture from the outside of the channel the latter being enveloped by a conducting material grid, two opposite slits being defined between the two edges of said C channel gap and a dielectric material wall located in front of said gap.

Abstract: A CO.sub.2 laser has a cylindrical housing of vitreous or ceramic material enclosing two confronting main electrodes which are connected across a trigger circuit, one of these electrodes being in conductive contact with a metallic layer surrounding substantially the entire outer surface of the housing to serve as an excitation electrode generating a corona discharge inside the housing. The gas in the housing is under substantially atmospheric pressure.

Abstract: A longitudinal-discharge-pulse laser has two coaxial sections in the form of glass tubes joined together by a grounded central electrode and terminated by two outer electrodes. Each glass tube carries on its outer surface a multiplicity of metal rings connected in parallel, via a step-up transformer, to the anode of a first thyratron for energization with a steep negative pulse to generate a corona effect for the preionization of a gas mixture in the tubes on command of a pulse-cadence generator. This generator also controls a second thyratron, with a predetermined delay, which applies negative trigger pulses to the two outer electrodes for initiating a pumping discharge of the laser.

Abstract: In order to focus the beam of a laser onto a receiving end of an optical fiber substantially coaxial therewith, the laser output is formed by a planoconvex lens with a semitransparent flat face confronting the laser cavity and an antireflecting curved face turned toward the fiber. Alignment of the laser beam with the fiber axis is accomplished by the adjustment of two oppositely pointing juxtaposed wedges interposed between the lens and the laser.

Abstract: A pair of excitation electrodes in a laser cavity, filled with a gas mixture at substantially atmospheric pressure, are connected across a pumping capacitor by way of part of the winding of an autotransformer in series with a pre-ionizing device within the cavity acting as a trigger switch. The pre-ionizing device comprises a dielectric tube carrying a plurality of axially spaced-apart metal rings constituting a condenser chain, the rings being provided with pointed extensions confronting one another to serve as corona electrodes. Contral pulses applied to a conductor inside the tube cause a spark discharge through the cascaded corona gaps of the trigger switch with resulting energization of the autotransformer and discharge of the pumping capacitor across the excitation electrodes. The metal rings may be interconnected by high-ohmic resistors establishing a uniform field distribution therebetween.