Integrated optical circuits having drop-in locations for optical circuit elements

Abstract

A plurality of mask images defines an optical circuit image in photoresist. Each of the mask images comprises parts of the optical circuit and the totality of all mask images together defines an optical circuit. The optical circuit is thus made up of plural optical elements some of which may be positioned in drop-in locations within the boundary of another optical circuit element. A photolithography system globally aligns and exposes the mask images in photoresist. The resultant composite image is substantially indistinguishable from a single image of the entire optical circuit. Different images for each of the mask image parts can be substituted with other images or image parts and thereby exponentially increasing the number of circuit permutations from a predetermined number of available mask images. A unique optical circuit, for example, can be generated from a pre-existing library of reticle images. The images are printed in predetermined locations on a substrate to define the desired optical circuit. Thus, predefined second optical circuit elements can be dropped in (imaged or exposed) locations within a first optical circuit.