Hybrid polymer microlens arrays with high numerical apertures fabricated using simple ink-jet printing technique
Microlens arrays fabricated by a direct ink-jet printing of UV-curable hybrid polymer are reported. A periodic pattern of polymer drops was ink-jet printed on the surface-treated glass substrate and cured in the UV-light. Using this simple technique, we demonstrated periodic arrays of almost semi-spherical microlenses of 50 μm diameter size and a focal distance of 48μm. The optical characteristics of solitary μ-lenses and arrays comprising up to 64x64 microlenses are measured both in the near- and far-field zones. Large numerical aperture and short focal distance make the ink-jet printing of microlenses very attractive for applications in optical interconnects, large 2D VCSEL arrays and pixelated imagine sensors utilizing CCD or SPAD arrays, offering thus an efficient, simple and a cheap alternative to the conventionally used photolithography technique.