Abstract

Optical microsystems formed by the planar integration of micro-optical elements on a transparent slab are of considerable interest as compact, robust microsystems for applications in sensors and optical instruments. In a typical such microsystem [1], a sequence of micro-optical elements are arranged on one surface of a slab substrate which folds the optical paths between the elements by reflection at the opposite surface (Fig. 1). A major advantage of this approach is the ability to fabricate all micro-optical elements as one block, thus avoiding subsequent positioning and alignment steps. This can readily be achieved by the use of ‘planar’ (micrometer relief) micro-optical elements. Most commonly they are fabricated in a fused silica slab either as binary optical elements, by conventional multiple resist lithography and etching steps [1], or as continuous-relief elements, by techniques such as direct laser or e-beam writing or halftone lithography followed by transfer into the slab material by proportional etching [2].

© 1998 Optical Society of America