Siemens Aktiengesellschaft

Gerhard Brumme

Ludger Grage

Hinrich Heynisch

Erwin Hubner

Wolfgang Kranz

Konrad Paur

A method and apparatus detects and identifies targets using a laser and operating in accordance with Doppler radar techniques. A laser sensor comprises a laser transmitter and an optical superheterodyne receiver and detects characteristic surface vibrations of targets and derives, from the laser echo signals, after frequency conversion and demodulation, low frequency oscillations having the frequencies of the vibration spectrum, from which, through comparison with patterns of known targets, provides detection and identification of the target.

Method and apparatus for recognizing and identifying targets

An optical resonator has two resonator mirrors disposed opposite one another on a mirror carrier which is divided at an angle relative to a perpendicular plane to the optical axis. Precise adjustment of the mirror spacing is provided by movement along the abutting faces at the dividing plane to match the mirror spacing to the wavelength of the laser emission for frequency tuning.

Optical resonator for a laser

A transversally excited gas laser whose main discharge is initiated by a corona discharge triggered between auxiliary electrodes. The auxiliary electrodes are thereby respectively composed of a conductor which is enveloped by a jacket of dielectric which forms a single part. The jacket is provided with an incision between the two conductors parallel to the longitudinal axis, facing the main discharge path, and also is metallized at its outside. The incision projects UV light of the corona discharge into the region of the main discharge path and thus generates free electrons where they are most effective. The outside metallization increases the capacitance of the auxiliary electrode arrangement; and as a result, the corona discharge is intensified. The main discharge may possibly also be delayed such that the firing ensues in a more greatly ionized gas. The result is that the laser becomes more independent of changes in the high voltage, the gas pressure and the gas composition and thus may be used in sealed-off CO.sub.2 lasers for mobile employment.

Transversely excited gas laser and method for the operation thereof

A transversely excited gas laser, includes: an elongated gas-filled discharge chamber having an optical axis; a main cathode electrode and a main anode electrode extended along the optical axis in the discharge chamber defining a main discharge space between the main cathode and the main anode electrodes through which the optical axis extends, the main electrodes bordering two sides of the main discharge space leaving two other sides open; two pairs of auxiliary electrodes each being extended parallel to the optical axis in vicinity of a respective one of the open sides of the main discharge space and mutually spaced apart by a given distance, each of the auxiliary electrodes including a conductor and a dielectric shell surrounding the conductor, each of the auxiliary electrodes being spaced from all of the other electrodes by a set breakdown distance; and a driving unit connected to the electrodes, the driving unit supplying different potentials to the main cathode and main anode electrodes producing a main electric discharge therebetween during operation of the gas laser, and the driving unit supplying different potentials to the pairs of auxiliary electrodes causing a corona discharge preionizing the gas in the main discharge space to take place therebetween across the given distance during operation of the gas laser.

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Eching, Germany

Gerhard Brumme