Abstract: An algorithm-driven digital ultraviolet (UV) lithography (DUL) method and apparatus used to fabricate high-quality optical waveguide and many other kinds of high-resolution microstructures without the use of a photomask. Instead of the use of an actual photomask, a virtual mask based on a spatial light modulator is used. The DUL method and apparatus can compensate for a proximity effect caused by light scattering and make the exposure adaptive to a nonlinear response curve of a photoresist, in which an exposure dose-map is created based on the bitmap of a designed pattern together with the optimization parameters determined by system configuration and the photoresist. To fabricate large-area patterns, a plurality of sliced exposure dose-submaps with transition zones that can depress the stitching error caused by mechanical mispositioning are generated for digital lithographic exposure process.