Patent ID: 6943964

Claim:
A system for shaping a laser beam from a non-uniform spatial profile to a flat-top or uniform spatial profile comprising: an input laser beam having an input energy density and a maximum beam radius; a system magnification factor; a lens including a first and second aspheric surface; a central ray having a central optical path length; a plurality of arbitrary rays having an optical path length equal to said central optical path length; said first aspheric surface having a curvature profile defined by the equation: Z =( n 2 2 −n 0 2 ) −1 {[( n 1 n 2 −n 0 2 ) z+n 2 C]±n 0 [( C+n 1 γ 1 n 2 z ) 2 +( n 2 2 −n 0 2 )( R−r ) 2 ] 1/2 } (4); and said second aspheric surface having a curvature profile defined by the equation: z ′={( R−r )( Z−z )±γ 1 ( R−r )[( Z−z ) 2 +( R−r ) 2 ] 1/2 }/[(γ 1 2 −1)( Z−z ) 2 +γ 1 2 ( R−r ) 2 ] (6) where n 0 is the refraction index of the medium, n 1 is the refraction index of said first aspheric surface, n 2 is the refraction index of said second aspheric surface, r and z are the radial and axial values at said first aspheric surface, R and Z are the radial and axial values at said second aspheric surface, C is a constant determined at the condition where the optical path length of said arbitrary rays are equal to said optical path length of said central ray, and γ 1 =n 1 /n 2 .