Device for measuring performance of a laser beam, comprises mirror with substrate transparent for the laser beam, and photo receiver arrangement, where mirror has reflective layer on rear surface facing towards an incident laser beam

摘要

The device for measuring performance of a laser beam (10), comprises a mirror (11) with a substrate (12) transparent for the laser beam that has a reflective layer (14) having same reflectance on a rear surface (13) facing towards an incident laser beam; and a photo receiver arrangement arranged at a circumference area of the substrate that delivers an output signal corresponding to a laser beam power to be measured. The substrate is a plane parallel plate. A peripheral surface of the substrate is a cylinder surface, whose cylindrical axis is parallel with an optical axis of the laser beam. The device for measuring performance of a laser beam (10), comprises a mirror (11) with a substrate (12) transparent for the laser beam that has a reflective layer (14) having same reflectance on a rear surface (13) facing towards an incident laser beam; and a photo receiver arrangement arranged at a circumference area of the substrate that delivers an output signal corresponding to a laser beam power to be measured. The substrate is a plane parallel plate. A peripheral surface of the substrate is a cylinder surface, whose cylindrical axis is parallel with an optical axis of the laser beam. The photo receiver arrangement comprises a first photo receiver and a second photo receiver such as photo diode that are circumferentially arranged at the peripheral surface of the substrate. The first photo receiver is arranged in a peripheral region that lies towards the incident laser beam to measure the performance of the incident laser beam. The second photo receiver is arranged opposite to measure the performance of a radiation that occurs contrary to the direction of the laser beam. Scattering- or collective elements made form the substrates for the laser radiation are arranged between the peripheral surface of the substrate and the photo receiver. A filter is arranged between the peripheral surface of the substrate and the photo receiver that pass through the radiation to be measured to the photo receivers. The mirror is a beam-deflecting mirror whose reflecting layer or layers has the reflectance of more than 99.5%. The mirror is a beamsplitter mirror whose reflecting layer or layers has the reflectance of 10-90%. An independent claim is included for a laser processing head.