Novel method of fabrication of diffractive microlens arrays

A new method, self-alignment process is introduced to fabricate microlens arrays. By this method, during fabrication process, the rigorous alignment, which has great effect on diffraction efficiency in the conventional multi-photolithography process, is avoided. The large arrays of 1500 × 640 element silica microlens with 8-phase-level are manufactured by this method. The measurement results show that the 8-phase-level microlens arrays diffraction efficiency is as high as 93%, which is higher than by the conventional method.