Alignment difficulties in optical computing arrangements are overcome by integrating the optical components on a single substrate and arranging the elements in a manner that causes them to interact with one another to perform the desired function. The substrate has one or two major surfaces and the elements are grown or fabricated on those surfaces using conventional integrated circuit manufacturing techniques. Recognizing that an optical circuit can be larger than what can be fabricated on a single substrate, aligning structures are fabricated onto substrates that need to be coupled to form the optical circuit. The aligning structures contain registrable protrusion and indentation portions, such as ridges and grooves, that are imbedded into the substrates as part of the manufacturing process of the optical elements. Most advantageously, the position-sensitive optical devices are manufactured on one side.