Thomson Licensing

University of Central Florida Research Foundation, Inc.

Eads Deutschland Gmbh

Jos. Schneider Optische Werke Gmbh

Luphos Gmbh

Theo Tschudi

Nelson V Tabirian

Bernhard Braunecker

Thorsteinn Halldorsson

Boris Zel'dovich

Somakanthan Somalingam

Thomas Vogeler

Mathias Hain

Palmi Petursson

Lingli Wang

A method for zero-contact measurement of the topography of a spherically or aspherically curved air-glass surface of an optical lens or lens combination, distinguished in that the surface (S) to be measured is sampled on its glass rear side with an optical measurement beam through the air-glass surface (S) lying before it in the measurement direction. A device for carrying out the method is characterized in that

Method for zero-contact measurement of topography

The invention relates to an optical compensation element comprising a first transparent surface on which a transparent electrode is arranged; a second transparent surface on which a plurality of transparent main electrodes are arranged, several of which being respectively connected to control electrodes via a transverse electrode; and a material having a refractive index which changes according to the voltage applied, said material being arranged between the first and second transparent surfaces. The aim of the invention is to improve said compensation element. To this end, each main electrode is connected to a transverse electrode at a precise location.

Optical compensation element

A method for the elimination of image speckles in a scanning laser projection is suggested, in which a phase hologram is used for dividing the illumination beam of the projector into partial beams. The partial beams are heterodyned again on the image screen within the image element (pixels) to be projected in such a way that differing speckle patterns are formed which average each other out in the eye of the viewer over time and/or space. Thus, a device is provided especially for the laser projection which substantially eliminates or reduces the speckles at the viewer. However, the beam form and the beam density are hardly or not changed.

Method and device for eliminating image speckles in scanning laser image projection

Meters detect power parameter information about laser beams using liquid crystals to propagate the beam therethrough with photodiode detectors. The power parameters include intensity in watts per square meter, beam waist size, and the location of the focal spot based in light induced orientational phenomena in the liquid crystal. The detectors can can count the number of interference fringe rings produced by a laser beam passing through the liquid crystal(LC). Alternatively, the time between the occurrence of each interference fringe ring can be measured to determine the power parameters. A preferred embodiment has a standard liquid crystal oriented at approximately 45 degrees to the axis of an incoming laser beam to be measured. The beam passing through the LC can be centered through a pinhole on a planar plate causing the interference fringe rings to appear on the surface of the plate. An alternative embodiment measures intensity based on determining the voltage necessary to produce fringe ring patterns. Corresponding the fringe ring patterns to intensity values can be done manually upon visual observation and calculation or automatically by computer.

Apparatus and method for measuring the power density of a laser beam

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Darmstadt, Germany

Theo Tschudi