Highyag Lasertechnologie Gmbh

Ii-vi Delaware, Inc.

Directphotonics Industries Gmbh

Haro Fritsche

Bastian Kruschke

Ralf Koch

Fabio Ferrario

Stefan Heinemann

Wolfgang Gries

Andreas Grohe

A spectral beam combiner is based upon a specialized diffraction grating that is intentionally configured to create output signals along two separate paths, each path supporting a spectrally-combined beam. One path supports the propagation of a majority of the spectrally-combined beam (e.g., 80-95%) and is defined as the output path from the beam combiner. The remainder of the spectrally-combined beam is directed along a separate path and into an external cavity arrangement used to perform wavelength stabilization. Either reflective or transmissive diffraction gratings may be used, with different diffraction orders and/or polarization states of the spectrally-combined optical beam used to create the output beam and the separate wavelength stabilization feedback beam.

Spectral beam combiner with independent wavelength stabilization

The present invention relates to a diode laser with external spectrally selective feedback. It is an object of the invention is to provide an external cavity diode laser with wavelength stabilization which allows an increased overall output power in the desired wavelength range. According to the invention, an external cavity diode laser arrangement is disclosed comprising: an active medium positioned inside an internal laser cavity (), the internal laser cavity () comprising an exit facet () adapted for outcoupling laser radiation; an external frequency-selective element () positioned outside the internal laser cavity () and adapted for wavelength stabilization of the laser radiation; a beam divider () positioned outside the internal laser cavity () and adapted to divide the outcoupled laser radiation (BO) into a first beam (B) extending along a first beam path (P) and a second beam (B) extending along a second beam path (P), the first beam (B) having higher radiant intensity than the second beam (B) and the first beam path (P) being different from the second beam path (P); and an intensity control means to control the radiant intensity incident to the external frequency selective element (); wherein the external frequency-selective element () and the intensity control means are arranged in the second beam path (P). The intensity control means in the second beam path (P) may comprise a polarization modifying means () and a polarizer () in order to reduce thermal stress at the frequency-selective element ().

Diode laser

The invention discloses a device for laser material machining, with at least two laser beam sources (-) which emit laser beams (-) of different wavelengths, with associated beam imaging means (-), to configure appropriately the beam paths of each associated laser beam (-), a beam superposition device (), to overlay the laser beams (-) on each other, and imaging optics (), to image the overlaid laser beams (-) onto a workpiece () so that respective focal points are associated with the laser beams (-) in the focus of the imaging optics () on the workpiece (), wherein the beam imaging means image the laser beams (-) onto the respective focal points in a predefined arrangement which can be varied by means of the beam imaging means (-). According to the invention, electronic control devices (-) are provided which are able to vary each of the outputs of the laser beams (-) with a high frequency to vary the intensities of the respective focal points at the focus of the imaging optics () in a predefined manner. In this way, a high frequency control of the parameters of laser material machining which can be combined with conventional modulation techniques is implemented.

Device and method for laser material machining

Growing community of inventors

Berlin, Germany

Haro Fritsche