Abstract:. In the recent years a significant progress was achieved in the field of design and fabrication of optical systems based on freeform optical surfaces. They provide a possibility to build fast, wide-angle and high-resolution systems, which are very compact and free of obscuration. However, the field of freeform surfaces design techniques still remains underexplored. In the present paper we use the mathematical apparatus of orthogonal polynomials defined over a square aperture, which was developed before for the tasks of wavefront reconstruction, to describe shape of a mirror surface. Two cases, namely Legendre polynomials and generalization of the Zernike polynomials on a square, are considered. The potential advantages of these polynomials sets are demonstrated on example of a three-mirror unobscured telescope with F/#=2.5 and FoV=7.2x7.2°. In addition, we discuss possibility of use of curved detectors in such a design.
Nd-phospate glasses with a great laser effect are described. They have large induced-emission cross sections and low thermal distortion. Those glasses can be used in small and medium laser equipment for processing of materials and for measuring techniques. Addition of fluorine (fluorophosphate glasses) produces a lowering of the nonlinear refractive index. Those glasses are particularly suitable for the final stages of large amplifier chains for nuclear fusion experiments. The nonlinear refractive index can be reduced as low as 0.5 x 10(-13) esu.
Optically active tert-leucinol is an important building block in asymmetric synthesis. However, the ( R ) enantiomer particularly has so far remained difticult to obtain, mainly because of the laborious synthesis of the precursor amino acid, (R)-tertleucine. Here we present a new, classical resolution of racemic tert-leucinol, which allows straightforward preparation of each, but especially the ( R ) enantiomer, in good yields and high optical purities. The feasibility of the synthesis of useful derivatives is demonstrated by transformation into the corresponding (R)-4-tert-butyl-2-oxazolidinone.
Curved sensors are a suitable technological solution to enhance the vast majority of optical systems. In this work, we show the entire process to create curved sensor-based optical systems and the possibilities they offer. This paper defines the boundaries of the reachable curvatures for a full range of monolithic sensors. We discuss how the curved focal plane shape is related to the imaged scenes and optical parameters. Two camera prototypes are designed, realized and tested, demonstrating a new compact optical architecture for a 40 degree compact objective, as well as a wide field fisheye zoom objective using a convex sensor to image a 180 degree field of view.
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