Achromatic hybrid triplet objective on one-only glass

摘要

The possibility of chromatic aberration correction in a hybrid (refractive-diffractive) objective is investigated. Such objective is composed of refractive lens (or lenses) and a diffractive microstructure deposited on any of the objective surfaces. To satisfy the achromatisation condition it is enough to use one glass and a diffractive corrector, however thanks to splitting the refractive component onto two separate lenses made of the same glass we have additional possibilities to correct better monochromatic aberrations. In this paper conditions for such design are discussed and exemplary triplet objectives are designed. The presented objectives have relative aperture as high as 1:2.5 or 1:3 and maximum field-of-view angle 7.5degrees or 15degrees respectively. [References: 7]