Micro-optic fabrication with subdomain masking.

An innovative fabrication technique is introduced that is based on multiple-exposure techniques for micro-optics fabrication. This approach is compatible with conventional lithography systems used in integrated circuit manufacturing and can be applied to thick and thin photoresists and is based on additive lithographic techniques introduced elsewhere [Appl. Opt. 41, 6176 (2002)]. We chose a simple subdomain basis set to transform the two-dimensional basis patterns into a family of various three-dimensional micro-optic elements using exposure control to modulate the third dimension. We demonstrate the capability to sculpt the photoresist into a variety of three-dimensional micro-optic elements by performing multiple exposures using elements from the subdomain basis set, without resorting to multiple etching steps.