Abstract: A method for determining wavefront shapes of a multi-spectral signal light beam from a single signal image acquisition of said multi-spectral signal beam, with a device including an optical assembly made at least of an optical mask and an imaging sensor, notably a matrix imaging sensor, for generating and recording intensity patterns of incident beams, by having these beams reflect on, or propagate through, the optical mask. The optical mask having the optical properties: i) to cause the intensity pattern to depend on the wavefront shape, so that a tilt applied to the wavefront shape results in a displacement amount of the intensity pattern, and ii) to produce uncorrelated intensity patterns over at least one surface area A of the imaging sensor, for a plurality of respective incident monochrome beams of different wavelengths having a same wavefront shape.

Abstract: In a screw compressor for gaseous media, in particular refrigerants, comprising a compressor housing, two screw rotors arranged in screw rotor bores in the compressor housing, which are rotatingly drivable and interact to compress the medium, and a control slide arranged adjacent the screw rotors and movable in a direction of displacement for controlling the compression of the screw compressor, in order to solve the problem that the compression of the screw compressor can be controlled, but not precisely regulated, it is proposed that a scannable element, which is scannable with a measuring sensor so as to recognize a position of the control slide in the direction of displacement, be coupled with the control slide.