Lenses design

The main body of the cell, shown in figure 10.12, was a cylindrical Pyrex tube of diameter 10 cm and length 2 m, sealed at the ends with Teflon lenses designed to... 

Leutz R, Suzuki A (2001) Nonimaging fresnel lenses - design and performance of solar concentrators. Springer, Berlin... 

To remain safe and efficacious on the eye, contact lenses must maintain clear and wetted surfaces, provide an adequate supply of atmospheric oxygen to and adequate expulsion of carbon dioxide from the cornea, allow adequate flow of the eye s tear fluid, and avoid excessive abrasion of the ocular surface or eyeflds, all under a variety of environmental conditions. The clinical performance of a contact lens is controlled by the nature of the lens material the lens design the method and quaUty of manufacture the lens parameters or specifications prescribed by the practitioner and the cleaning, disinfection, and wearing procedures used by the patient. 

The principal problems for sdicone mbber as a viable lens material are the nonpolar nature, which gives Hpid deposits and wettabdity problems and the tendency to adhere to the cornea. Efforts to modify the sdicone lens surface for improved wettabdity have achieved limited success. These efforts include grafting hydrophilic monomers, such as HEMA, GM (150), and NVP (151—153), to the lens surface and plasma treatments of finished lenses. Efforts to improve the movement of sdicone lenses on the cornea with various lens designs have not been successfld, and the cause of lens—cornea adherence, which is not an exclusive problem of sdicone lenses, is an active area of research. 

Cast molding is an increasingly used manufacturing process for both rigid gas-permeable and hydrogel contact lenses. In this process, two molds, made from a variety of plastics, are used. A female mold forms the lens front surface (convex) and a male mold forms the lens back surface (concave). The plastic molds are made from metal tools or dies that are usually stainless steel, precision lathed, and polished to the specified lens design. A variety of mold materials are used. The polymerized, hardened lens is released from the mated molds and is processed in much the same way as the spin-cast lenses described above. 

The ECAP incorporates an electrostatic lens in the time-of-flight spectrometer in order to improve the mass resolution by compensating for small spreads in the energies of the ions evaporated from the specimen under the pulsed electric field. A lens design by Poschenrieder or a reflectron type of electrostatic lens is used for this purpose, and is standard equipment for metallurgical or materials applications of APFIM. These typically improve the mass resolution at full width half maximum (FWHM) from m/Am 250 to better than 2000. 

Handbook of Lens Design, Daniel Maiacara and Zacarias Malacara... 

Lens Design Second Edition, Revised and Expanded, Milton Laikin... 

Entropy and Information Optics, FrancisT. S. Yu Computational Methods for Electromagnetic and Optical Systems, John M. Jarem and Partha P. Banerjee Laser Beam Shaping, Fred M. Dickey and Scott C. Holswade Rare-Earth-Doped Fiber Lasers and Amplifiers Second Edition, Revised and Expanded, edited by Michel J. F. Digonnet Lens Design Third Edition, Revised and Expanded, Milton Laikin Handbook of Optical Engineering, edited by Daniel Malacara and Brian J. Thompson... 

Chou, C.-H., Khuri-Yakub, B. T and Kino, G. S. (1988). Lens design for acoustic microscopy. IEEE Trans. UFFC 35,464-9. [54, 55]... 

Hardware limitations in the deep-UV region revolve around lens design (and fabrication) and source brightness. The lens problem is a materials-related issue in that the number of optical-grade materials with acceptable... 

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