Optically encoded glass-coated microwire

Abstract

A drawn glass-coated metallic member has a thermal contraction coefficient differential such that the thermal contraction coefficient of the glass is less than that of the metallic member. The thermal contraction coefficient differential is maintained within a predetermined range during drawing. Drawn glass is placed under residual compression, interfacial bonding between said glass and said wire is substantially uniform, and surface cracking and bond breaks between metal and glass are substantially prevented. Optical properties of the glass coated microwire provide a basis for enabling multi-bit encoding capability. Advantageously data encoding is achieved optically, magneto-optically or using a combined magnetic and optical encoding mechanism. The duplex material constitution of the glass coated microwire permits imparting of data thereon by selection and processing of the glass. Data implantation is readily achieved in-line, during an initial drawing operation, or as a separate post-draw process. Reading of data on optically encoded glass coated microwire is readily accomplished by optical or magnetic methodology, or a combination thereof.