Achromatic hybrid diffractive-refractive lens

Hybrid elements contained optical power with both diffractive and refractive components are shown to be useful for obtaining achromatic dispersive characteristics. In the achromatic case, the optical power of both refractive and DOE components are of the sem sign resulting in much smaller glass curvatures than in all-refractive achromatic doublets. A comparison is made between Hybrid achromatic and equivalent traditional system in the visible wave band to seek advantages and disadvantages.