From: r_delaney2001@yahoo.com   
      
   Lasers are useful for their low dispersion.   
      
   What I wonder is, why are they necessary for the   
   most common applications?  e.g. bar codes, CD readers,   
   etc.   
      
   My point is that collimated, non-coherent light   
   was developed long before the laser.  So what makes   
   a laser superior?   
      
   --   
   Rich   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)