Improving the brightness of a multi-kilowatt single thin-disk laser by an aspherical phase front correction.

We report on results obtained with an aspherical mirror to compensate for the phase front aberrations of a cw thin-disk laser with a single disk in the resonator. A record output power of 5 kW with a beam quality suitable for laser cutting (beam propagation factor M2=9.2) has been achieved.

Highly efficient three-level blazed grating in the resonance domain.

We designed, fabricated, and characterized three-level transmission gratings in the resonance domain with reduced shadowing losses based on a three-wave interference mechanism. A new technological approach allows for fabrication of homogeneous and large area multilevel gratings without spurious artifacts. To our knowledge, the measured efficiency of 86% exhibits the largest value yet reported for a multilevel transmission grating in the resonance domain close to normal incidence.

Microoptical telescope compound eye.

A new optical concept for compact digital image acquisition devices with large field of view is developed and proofed experimentally. Archetypes for the imaging system are compound eyes of small insects and the Gabor-Superlens. A paraxial 3x3 matrix formalism is used to describe the telescope arrangement of three microlens arrays with different pitch to find first order parameters of the imaging system. A 2mm thin imaging system with 21x3 channels, 70 masculinex10 masculine field of view and 4.5mm x 0.5mm image size is optimized and analyzed using sequential and non-sequential raytracing and fabricated by microoptics technology. Anamorphic lenses, where the parameters are a function of the considered optical channel, are used to achieve a homogeneous optical performance over the whole field of view. Captured images are presented and compared to simulation results.