Many laser applications need a homogeneous - so called flat hat - light distribution in the application area. However,
many laser emit Gaussian shaped light. The technology of diffractive optical elements (DOE) can be used to shape the
Gaussian beam into a flat hat beam at a compact length. SCHOTT presents a DOE design of a flat hat DOE beam shaper
made out of optical glass. Here the material glass has the significant advantage of high laser durability, low scattering
losses, high resistance to temperature, moisture, and chemicals compared to polymer DOEs. Simulations and
measurements on different DOEs for different wavelength, laser beam width, and laser divergence are presented.
Surprisingly the flat hat DOE beam shaper depends only weakly on wavelength and beam width but strongly on laser
divergence. Based on the good agreement between simulation and measurement an improved flat hat DOE beam shaper
is also presented.
This paper discusses the use of diffractive optical elements (DOEs) and micro-optics
fabricated by precise pressing in glass for beam shaping of high-power diode lasers.
The DOEs are used to diffract the light into the point of interest and to improve the laser
beam quality. We have realized circular, flat-top and multi-beam intensity profiles. The
highest measured diffraction efficiency was higher than 95 %. The new established
fabrication process has potential for mass production of DOEs. SCHOTT's precision
glass molding process guarantees a very constant quality over the complete production
The current trend that calls for miniaturization of the optical components used in digital and cellular phone cameras will continue to play an important role. Aspherical lenses are taking on greater importance because a single asphere can be used to replace several spherical lenses and, thus, reduce the overall size and weight of the optics. At the same time, aspheres allow for an improved image quality and a higher resolution of the phone camera system.
This paper discusses the precise pressing technology for the fabrication of diffractive optical elements (DOEs). The new established fabrication process allows mass production of DOEs in high homogeneous optical glasses. Our precise pressing process guarantees a very constant quality over the complete production chain. Glass DOEs made by SCHOTT AG are planar optical phase elements with highly accurate shape and efficiency. The blazed profile of the diffractive optical elements was approximated by a stepped profile with up to sixteen phase levels. The highest measured diffraction efficiency for sixteen level gratings was 95%.