On Tuesday, November 5, 2013 10:20:08 AM UTC-5, Gashaw Melesse wrote:   
   > On Tuesday, November 5, 2013 3:18:48 PM UTC+1, Phil Hobbs wrote:   
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   > > On 11/05/2013 07:00 AM, Gashaw Melesse wrote:   
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   > > > I have been trying to design an asymmetrical Fresnel lens for   
   illumination purpose. The commercial software that I have at hand is Zemax.   
   And in this software Fresnel lens are defined for only rotational symmetric   
   surfaces.Is there anyone who knows    
   how to implement it in that software in different way or is there any other   
   option?   
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   > > > Thank you.   
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   > > Making the mould for a general asymmetrical Fresnel lens could be a bit    
   > > pricy.  Hard to machine, and a lot of surface relief for binary optics.    
   > >   Why do you need something so fancy for such an apparently mundane    
   > > application?   
   > > Cheers   
   >    
      
   > > Phil Hobbs   
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   > > --    
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   > >    
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   > > Dr Philip C D Hobbs    
   > >    
   > > Principal Consultan    
   > >    
   > > ElectroOptical Innovations LLC    
   > >    
   > > Optics, Electro-optics, Photonics, Analog Electronics   
      
   > Thank you for your reply.    
   >    
   > The purpose is to create an asymmetrical light distribution like in street   
   light application where the illumination has to be longer than broader.   
      
   OK silly idea, can you just make it two cylindrical (Fresnel) lenses?     
   It would seem that would be at least easy to define.   
      
   George H.   
      
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