Abstract: An apodizing filter is disclosed comprising two solid bodies of transparent material the first of which is struck by the incident light while the second receives the light from the first. The second body has a curve surface approaching the first body at a distance therefrom not greater than some wavelengths of the incident light. The plane tangent to the curve surface of the second body at the point of minimum distance from the first one forms with the direction of the incident light an angle greater than the limit angle of the total reflection related to the first body with respect to the medium in which the filter is sunk. The indexes of refraction of the two materials of which the two bodies are made are such that the light incidence on said tangent plane is lower than the limit angle of the total reflection. The combination is disclosed of the apoditic filter according to this invention with a mirror and an example is given of the filter application to a laser cavity.

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: An interferometer wherein the deviator element, that is the means whereby the interferometer optical elements are optically coupled together, the incident beam is admitted into the interferometer, and the beams to be made to interfere with one another are extracted therefrom comprises, according to a first embodiment a prism whose faces are uncoated and according to a second embodiment a diffraction grating. Basing on the above concept various optical arrangements are described which are referable to known arrangements such for instance the Fox-Smith, the Michelson, the Petrun'kin interferometers wherein the deviator element is replaced, according to this invention by a prism or by a diffraction grating functioning as reflectors. Specifically the use is disclosed of an interferometer as an output coupler of a laser optical resonator.

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.