Messerschmitt-boelkow-blohm Gesellschaft MIT Beschraenkter Haftung

Messerschmitt-boelkow-blohm Gmbh

Messerschmitt-bolkow-blohm Gmbh

Daimler Chrysler Ag

Micro Systems Design Dr. Altmann Gmbh

Konrad Altmann

Thorsteinn Halldorsson

Gunthard Born

Ernst-August Seiffarth

Thorstein Halldorsson

Ernst A Seiffarth

Laser amplification system

An optical sensor device for recognizing optical irradiation and detecting its direction is constructed as a spherical-shell section from dielectric, optically transparent material. The irradiation penetrating into the spherical-shell section is reflected back and forth between the exterior and the interior surface or between a mirror and a thin shell via an air gap or vacuum gap, and is thus deflected to the shell edge. Since signals of different intensities are received at the irradiation detector at the beam edge according to the direction of incidence, the direction of incidence of the irradiation can be determined from the relationship of the signals.

Optical sensor device using a dielectric transparent spherical-shell

An optical wide angle sensor head for directionally sensing optical radiation is made of a plurality of individual sensor optical elements. Each sensor optical element is arranged at an input end of its own fiber optical conductor and has its own light entrance, its own field of view and its own individual optical axis. Neighboring fields of view may overlap each other. The fiber optical conductors lead to a transducer for converting the individual light signals into respective electrical signals. The individual sensor optical elements are arranged on a common mounting member in a housing so that the individual optical axes pass through a common intersection in front of said light entrances. The mounting member is a flat plate or a concave plate having a concave curvature facing in the viewing direction, whereby a spherical mounting is avoided.

Optical wide angle sensor head

An arrangement for position finding of a laser beam in a scattering medium with a laser transmitter and a laser receiver followed by an evaluation circuit. In order to be able to differentiate in the incoming laser radiation the unscattered coherent content and the scattered content, the laser transmitter is connected to a modulation circuit for intensity modulation of the transmitted laser beam with a characteristic modulation frequency (f.sub.L &gt;1/T.sub.s) with the pulse duration spread being T.sub.s, which a brief laser pulse experiences upon being scattered in the medium. In addition, the receiver is connected to an electronic frequency filter tuned to the characteristic modulation frequency. Thereby, essentially only the unscattered coherent content of the laser beam is utilized for evaluation.

Arrangement for determining the position of a modulated laser beam in a

A stable optical laser resonator is formed by two mirrors facing each other. At least one of the mirrors operates as a decoupling device for decoupling a coherent, pulsating laser beam from the resonator. For this purpose the decoupling mirror has a zone or zones which are permeable or partially permeable to the laser beam. These zones are located in predetermined areas of the mirror and the size of these zones is relatively small compared to the total effective mirror surface. Preferably, the active lasing medium is limited to a narrow cross-sectional area perpendicularly to the optical axis of the resonator. The narrow cross-sectional area has an approximately rectangular shape for enforcing the one-dimensional oscillation movement of a laser beam.

Stable optical laser resonator

In a gasdynamic laser in which the hot flowing lasing medium (e.g. CO.sub.2 --N.sub.2) is cooled by expansion in a Laval nozzle 1, liquid droplets are introduced into the expanding lasing medium to increase the cooling effect. The liquid can be water, preferably heavy water, from a container 4 pressurized by the laser medium in plenum 6 and introduced from pipes 3 into a region immediately before the nozzle neck 2 so as to be atomized and accelerated through the neck 2. Evaporation occurs downstream of the neck and causes an increase in the cooling. The droplets preferably have a size in the range 1-20 .mu.m and may contain dissolved CO.sub.2. The droplets may be dispersed in a super cooled gas which is then injected into the lasing medium.

Gasdynamic laser

A gasdynamic CO.sub.2 -laser in which the lasing medium is being cooled by expansion in a Laval nozzle, is operated in a way to amplify the cooling effect. This increased cooling is accomplished by introducing liquid droplets into the expanding lasing medium. These droplets are entrained by the flowing medium whereby the droplets are taken along with a speed corresponding approximately to the speed of the expanding lasing medium. The amplification of the cooling is accomplished by the evaporation of these droplets.

Method of operating a gasdynamic CO.sub.2 -laser

In a molecular laser a cold gas flow is mixed with the hot gas flow by inducing the cold gas flow through slots (13) arranged upstream of the neck (11) of the Laval nozzle (10) through which the hot gas stream flows. In this way a rapid mixing is accomplished for generating non-balanced conditions in a laser gas. Preferably the mixing takes place substantially in the nozzle neck.

Apparatus for mixing gases in molecular lasers

In a gasdynamic CO.sub.2 laser mixing of hot and cold gasses takes place simultaneously with causing an inversion. The cold gas is air supplied through a compressor at a pressure in the range of 1 to 10 bar into the combustion chamber. Preferably the compressor output is supplied to two points of the combustion chamber, namely a zone directly upstream of and adjacent to the Laval nozzle and a zone in the combustion chamber further removed from the Laval nozzle.

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Munich, Germany

Konrad Altmann