US Patent 7843653 Achromatic flat top beam shaping

There is provided an optical system and method for shaping a polychromatic light into a substantially uniform profile beam along a first axis. A polychromatic divergent light with having multiple wavelength components is provided with a dispersion of divergence. A collimation optic collimates the polychromatic divergent light. A shaping lens shapes the collimated beam into a shaped beam with a nearly uniform profile along the first axis, the dispersion of divergence causing a deviation from uniformity of the nearly uniform profile. A focusing optic focuses the shaped beam. A combination of the collimation and focusing optics shows a chromatic focal shift that compensates for said dispersion of divergence, so as to reduce the deviation from uniformity to obtain a profile with a substantially uniform intensity along the first axis, for all of said multiple wavelength components.