Design of hybrid refractive and diffractive collimator with high accuracy

Collimator is one of the key tools to assemble, correct, adjust and test optical instrument, and it is an important part of the measuring instrument. In order to improve the measure accuracy, based on the particular aberration property of the diffraction optical element, the hybrid refractive- diffractive aberration correction method is put forward. The diameter of the collimator is 80 mm, the focal length is 500 mm. The overall length is less than 550 mm. The resolution is less than 4.3″. Having been optimized, the maximum spot is 5.2 mm, and the modulation transfer function(MTF) at 50 lp/mm is over 0.8, better than the conventional method.