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   sci.optics      Discussion relating to the science of op      12,750 messages   

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   Message 11,504 of 12,750   
   Gash M to Helpful person   
   Re: Sagging a lens surface to zones   
   27 Nov 13 07:06:08   
   
   From: mgashaw@gmail.com   
      
   On Wednesday, November 27, 2013 3:39:38 PM UTC+1, Helpful person wrote:   
   > On Wednesday, November 27, 2013 8:54:35 AM UTC-5, Gash M wrote:   
   >    
   > > Hi all,   
   >    
   > >    
   >    
   > > I would like to write a routine (either in c or matlab) which can be used   
   to collapse a given conic or aspheric surface to Fresnel zones, which is   
   basically designing a Fresnel lens from a given lens entity(surface). Fresnel   
   Lens(FL) which has    
   prismatic facets is easy to implement.But in this case the facets have to be   
   conic(aspheric) and different ways of realizing the FL is possible like fixed   
   sag per zone and fixed zone spacing.That is the general goal. My problem is   
   breaking down this    
   problem into smaller pieces to make it easy for coding. Therefore, my question   
   is : what are the basic blocks that my code needs to have to construct a FL   
   from a given surface? A sample code would be appreciated.   
   >    
   > >    
   >    
   > > Thanks,   
   >    
   > >    
   >    
   > > Gash   
   >    
   >    
   >    
   > I hope you do realize that collapsing a curved   
   >    
   > surface to a flat Fresnel will result in different   
   >    
   > aberrations.   
   >    
   >    
   >    
   Thanks for the reply.You are right.But the orientation of the grooves for   
   different applications matters. In my case,I want the FL for collimation   
   purpose; so the groove out orientation is preferred.Moreover,since the   
   application is for illumination    
   aberration is not much a concern here.I know how to model conventional FL in   
   commercial products like Zemax.My interest is to write a code which can   
   collapse a given surface to Fresnel zones. Could you give me some guidance how   
   to start?   
      
   Thanks,   
      
   gash   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

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