Fabrication of Hybrid Microoptics Using UV Imprinting Process with Shrinkage Compensation Method

With increasing demand for compact aspherical optics in the field of imaging and optical data storage, fabrication technology for low cost micro aspherical optics has become a research priority. There are various types of micro aspherical optics, such as injection molded lens, glass molded lens, glass and hybrid lens. Among these types of lens, the hybrid is regarded as one of the most suitable because it combines good optical properties with low cost. The hybrid lens is fabricated by fabricating an aspherical layer on a spherical glass lens. To fabricate the hybrid lens at low cost, a UV imprinting process is preferred for its simplicity. However, in the conventional UV imprinting process volumetric shrinkage of the photopolymer causes various problems such as surface wrinkling and asymmetric local shrinkage. To overcome such limitations of the UV imprinting process, a shrinkage compensation method using an iris diaphragm to control the direction of polymerization is proposed and analyzed experimentally. To evaluate the proposed UV imprinting process, a hybrid lens was designed and fabricated, and its geometrical property was measured and compared with the design value.