36 research outputs found
Precision manufacturing of a lightweight mirror body made by selective laser melting
This article presents a new and individual way to generate opto-mechanical
components by Additive Manufacturing, embedded in an established process chain
for the fabrication of metal optics. The freedom of design offered by additive
techniques gives the opportunity to produce more lightweight parts with
improved mechanical stability. The latter is demonstrated by simulations of
several models of metal mirrors with a constant outer shape but varying mass
reduction factors. The optimized lightweight mirror exhibits of mass
reduction and a higher stiffness compared to conventional designs, but it is
not manufacturable by cutting techniques. Utilizing Selective Laser Melting
instead, a demonstrator of the mentioned topological non-trivial design is
manufactured out of AlSi12 alloy powder. It is further shown that -- like in
case of a traditional manufactured mirror substrate -- optical quality can be
achieved by diamond turning, electroless nickel plating, and polishing
techniques, which finally results in ~nm peak-to-valley shape deviation
and a roughness of ~nm rms in a measurement area of
m. Negative implications from the additive manufacturing are shown
to be negligible. Further it is shown that surface form is maintained over a
two year storage period under ambient conditions.Comment: 13 pages, 19 figures, online version (corrected proof
Recommended from our members
Micro-fluorescene lifetime and spectral imaging of ytterbium doped laser materials
We present the application of a confocal fluorescence microscope to the analysis of Yb-doped solid-state laser materials, with examples of Yb-doped crystals, photonic crystal fibers and fiber preforms made with different manufacturing processes. Beside the fluorescence lifetime image itself, a microscopic spectral fluorescence emission analysis is presented and spatially resolved emission cross sections are obtained. Doping concentration and its distributions and other laser optical parameters are measured, which help to analyze manufacturing steps. Further properties like photodarkening and saturation are addressed
Laser Cooling of Silica Glass
Laser cooling of a solid is achieved when a coherent laser illuminates the
material in the red tail of its absorption spectrum, and the heat is carried
out by anti-Stokes fluorescence of the blue-shifted photons. Solid-state laser
cooling has been successfully demonstrated in several materials, including
rare-earth-doped crystals and glasses. Silica glass, being the most widely used
optical material, has so far evaded all laser cooling attempts. In addition to
its fundamental importance, many potential applications can be conceived for
anti-Stokes fluorescence cooling of silica. These potential applications range
from the substrate cooling of optical circuits for quantum information
processing and cryogenic cooling of mirrors in high-sensitivity interferometers
for gravitational wave detection to the heating reduction in high-power fiber
lasers and amplifiers. Here we report the net cooling of high-purity Yb-doped
silica glass samples that are primarily developed for high-power fiber laser
applications, where special care has been taken in the fabrication process to
reduce their impurities and lower their parasitic background loss. The
non-radiative decay rate of the excited state in Yb ions is very small in these
glasses due to the low level of impurities, resulting in near-unity quantum
efficiency. We report the measurement of the cooling efficiency as a function
of the laser wavelength, from which the quantum efficiency of the silica glass
is calculated