Abstract: An optical system comprises a hybrid optical motherboard having a plurality of optical interconnections formed therein, and a connector. A connector region is formed in, but does not extend completely along, an edge portion of the hybrid optical motherboard. The connector region contains a number of optical interconnections, and the connector contains an optical device. The connector is connectible to the connector region to align the optical device of the connector with the optical interconnections contained in the connector region. The connector and the connector region each comprises first and second substrates made of crystalline material and containing intersecting planes which can be delineated by etching. Each first substrate is formed with etched alignment grooves, and each second substrate is formed with etched alignment grooves which are complementary to the alignment grooves of the associated first substrate.

Abstract: A method of measuring linewidth loss during the formation of microelectronic circuitry, including the formation of a test pattern constituted by a series of spaced bars on a photographic mask which is to be used to form a predetermined pattern on a substrate material. Either of the bars or the gaps between the bars have the same predetermined width. In the former case the gaps, and in the latter case the bars, have widths which differ incremently stepwise from one to the next. The series of bars are such that the ratio of the widths of one adjacent bar/gap pair is unity.The resultant pattern which is formed on the substrate as a complement of the test pattern is then inspected, and the position where the bar/gap width ratio of the resultant pattern is unity is noted. The linewidth can then be calculated loss from a knowledge of the size of the incremental step and the position of the bar/gap width ratio unity point on the resultant pattern.