Simple focusing and collimating of laser light can often be
accomplished by using a single lens element. However
the focused spot size, energy intensity and image quality
are all dependent on, not only the focal length, but also
the laser beam diameter, the lens radii and the center
thickness of the element. Since there are many different
lens radii combinations that could be used to achieve a
particular focal length, the task becomes one of finding
the best combination to minimize or eliminate lens aberrations.
A best form lens is a singlet lens which has been
optimized to have diffraction limited (< 1/4 wave) wavefront
distortion.
A Best Form Laser Lens will focus a laser beam of a given
diameter to the smallest spot size possible and the spot size is proportional to the input beam
diameter and the focal length of the lens.