Max-planck-gesellschaft Zur F&#xf6;rderung Der Wissenschaften E. V.

Fritz P Schaefer

Sandor Szatmari

Jan Jasny

Jethwa, Jaydev

A ring laser gyro has an optical resonator (12), forming a loop- or ring-shaped beam cavity, a lasing medium (14) arranged in the resonator for furnishing, when stimulated, two laser oscillation pulses circulating in the resonator in opposing directions, and a device for measuring the change in frequency and/or wavelength of the laser oscillation pulses as a function of the rotation of the resonator. A saturable absorber (16) is arranged in the laser resonator for the purpose of fixing the standing wave resulting due to the laser oscillation pulses circulating in the opposing directions as regards the laser resonator. Rotation of the laser resonator changes the wavelengths of the laser oscillation pulses circulating in opposing directions. The change in wavelength and/or the difference in the frequencies of the laser oscillation pulses constitute a measure of the rotation rate. No effect making it difficult to measure low rotary speeds in known ring laser gyros occurs in the present ring laser gyro.

Ring laser gyro with an absorber medium with the laser cavity

An apparatus for measuring the duration of single short optical radiation lses, particularly laser radiation pulses, by means of autocorrelation and two-photon ionization, contains a Mach-Zehnder interferometer (BS1, BS2, M1, M2) as beam splitter means for generating from a single input radiation pulse (10) two coherent component pulses (14, 16) propagating along two component beam paths (18, 20) each of which contains a section (18a20a) passing through a meausring zone (22) where they overlap, further a two-photon ionization detector having a measuring zone (22) and collector electrode means (36) and counter-electrode means (38) at which an electric output signal is available depending on the number of charge carriers generated in the measuring zone when the component beam pulses overlap, and a measuring system connected to the electrode means (36, 38). The collector electrode means (36) contains a number of strip-type collector electrodes which are to each other and electrically separated from each other and are located in a plane essentially parallel to the two component beam paths ( 18a, 20a) in the measuring zone and are oriented in the longitudinal direction essentially in the direction of the component beam path sections (18a, 22a) passing through the measuring zone (22).

Apparatus for measuring the duration of single optical radiation pulses

A laser with distributed feedback utilizes an active laser medium, especiy a dye solution contained in a cell, excited by a pump radiation beam that passes through an optical grating or like device, and an optical imaging system arranged between the optical device and the laser medium; the imaging system, in combination with the optical device, forms a striped pump radiation pattern in the laser medium. The optical imaging system contains a microscope lens in retro position, or another scale reducing or demagnifying lens system, and may optionally, include a variable-focus lens for altering the imaging scale and, therefore, the wavelength of the laser emission.

Distributed feedback laser

A laser device especially intended to generate ultrashort light pulses, wein the laser path is defined by an interferometer (I) providing substantially total reflection, a partial reflector (OM) for decoupling, and a stimulatable laser medium (D) between the interferometer and the partial reflector, the interferometer comprising a beam splitter (1, 2) through which the light pulses are transmitted substantially without loss to a total reflector (4, 5) which reflects the component beams back to the beam splitter, and a device (3) for varying the ratio of the path lengths travelled by the component beams between the beam splitter and the total reflector.

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Goettingen, Germany

Fritz P Schaefer