[Laser] Looking for ideas on building simple optics for an optical beacon

[Charles Pooley]

Kerry Banke <kbanke at qualcomm.com> wrote:
   
  >...What 
>options are there to devise simple optics to narrow down the vertical 
>beamwidth to perhaps 5 degrees while keeping the horizontal beam 
>width wide? I'd like to reduce the waisted vertical beam width. 
   
  What about making a cylindrical parabolic mirror?  If you take a rectangular lexan mirror and squeeze it along one axis, it will bow into a very nearly parabolic shape, with the reflecting side inside.
   
  Then position the emitter along the optical axis and centered along the other axis.  The light will be focussed in one dimention and not the other.
   
  By experimenting with the focal length and placement of the emitter relative to the focal line, you should be able to make the pattern you want.
   
  Also, you might search for cylindrical lenses or freznel lenses.
   
  Charles Pooley
  KD6HKU
  www.microlaunchers.com