A device transfer process "selectively occupied repeated transfer (SORT)" for resource-saving integration of polymer micro optics fabricated by "built-in mask" method

The device transfer process known as selectively occupied repeated transfer, which integrates thin-film device elements into a substrate with desired arrangement at one time using all-photolithographic methods, is demonstrated here. As the elements, 300-μm-diameter polymer waveguide lenses made of acrylic photo-definable material are formed on a poly-vinyl-alcohol (PVA)-coated glass substrate in a two-dimensional array with 450-μm pitch by UV light exposure through a "built-in mask." The lenses are transferred to a supporting substrate by solving the PVA in water, and are further transferred to a final substrate, on which catch-up sites that have stronger adhesion strength than the surrounding area are formed with a pitch of 1800 μm. Selective transfer of the lens to the catch-up site is observed.