Photolytic technique for producing microlenses in photosensitive glass

Abstract

A process is described whereby 2-D arrays of small diameter spherical lenses are produced in a homogeneous photosensitive glass by a photothermal technique. The mechanism of the lens formation is explained on the basis of the density change of the photonucleated microcrystalline phase developed relative to the unexposed glass. The lens formation is related to such variables as optical exposure, thermal schedule, glass thickness, and lens diameter. Optical characterization of the lenses produced by this technique was carried out by interferometric and MTF measurements. One-to-one conjugate erect imaging lens arrays were fabricated and tested.