Bentec Services Limited (Canada)

Software

Instructions: Save one of the following programs to your desktop or chosen folder, then execute the program icon from there - the World icon will represent the program. Only necessary support files will automatically be included in the download process.

Download Times: Less than 30 seconds.

Please note: Any suggestions are welcome regarding the illustration of these or other proposed programs. The purpose of the programs is primarily to illustrate nth- order Hyperaspherical surfaces and their independence of a conic constant. If you find them of interest I would be delighted to receive any considered observation, comment or suggestion.

If you have difficulty downloading the programs please let me know. 

FresnelMirrorWebProg.exe - HyperFresnel Mirror with data available for analysis. 3rd March 2002

BiFresnelWebProg.exe - HyperFresnel/Hypersurface lens with surface data available for analysis.

SuperFresnelWebProg.exe - Singlet lens -  dual Fresnel surfaces

HybridFresnelWebProg.exe - Hybrid Fresnel lens

HybridNullWebProg.exe - Interferometer lens-testing

HybridTestNullWebProg.exe - alternative to the above but using a standard asphere equation (with some restrictions) for the test surface.

HybridWebProg.exe

HyperCassegrainWebProg.exe - two mirror telescopes

HyperSchmidtWebProg.exe - Schmidt camera

Design and Fabrication of Compound Refractive X-ray Lenses for CHESS: Abstract: It has long been thought that focusing x-rays with refractive optics was inefficient, if not impossible. Recent developments, however, indicate this is not so. In this paper, we present our work which consisted of designing, building, and testing several compound refractive x-ray lenses for the Cornell High Energy Synchrotron Source (CHESS). We have achieved a gain of 2.5 with one such lens, while focusing a 12 keV beam to a width of approximately 10 microns. Such a beam could be used in various experiments due to its extremely small width and high intensity. Scott Forth PDF file

Note: Standard aspheric formulations incorporate a conic constant which, in addition to the conic base radius, defines the conic - which may be further modified by employing an extended polynomial (sometimes 20 terms) with aspheric coefficients. A comprehensive article by Scott A. Lerner and Prof. Sassian of the University of Arizona concerning 'Optical design with parametrically defined aspheric surfaces', addresses the general difficulties associated with the standard formulation for aspherical surfaces. This article was published in revised form on 12th June 2000, by Applied Optics and in association with the Optical Society of America. 

Regarding fabrication, a good source for research is Moore Tool Company in Connecticut, who manufacture the Nanotech 220UPL and 350FG and related systems suitable for mould tool insert manufacture and further injection moulding of polymer lenses. They also manufacture a grinder which will grind glass directly to aspheric profiles and near polished surface quality. They also provide test systems of high reliability. 

Regarding 'less expensive' fabrication techniques, much depends on volume of production. Clearly, polymer optics is cost effective in large volume as the major cost is associated with mould tool insert manufacture and set-up cost prior to injection moulding or replication by other means. On the other hand. It may be that an existing glass lens, for example, might simply require its surface modified to aspherical form in order to better its performance - achieved either by the removal of surface material or adding surface material using an optical resin. 

Back to the question of aspherical definition  I might mention that Hyperaspherical surfaces are independent of a conic constant and aspheric coefficients. This may become apparent if you download various programs available free from this web site. Hyperaspheres generate according to optical path difference. An insight into hyperaspherical optics may be achieved with reference to the theorem of Malus and Dupin and its converse. Ref: Principles of Optics (Born and Wolf) 

Further, hyperaspheres can control and steer non-spherical wavefronts, as desired. See reference

Stavroudis, O.N. 1987, Tracing Wavefronts: Can it be done? SPIE Vol.766 'Recent trends in optical design'  pp 18-26 

Hyperaspherical (nth-order) techniques and associated applications are the subject of on-going research by Bentec Services Limited. One objective is to generalize geometrical aspherical optics beyond the various standard formulations involving endless coefficients - for example, the following