Microsystems and wafer processes for volume production of highly reliable fiber optic components for telecom- and datacom-application

In realizing an efficient volume production of highly reliable active fiberoptic components the microsystem-technique was one of the most important factors. Micro-mechanical methods allow large scale fabrication of micro-optical silicon lenses with methods, machines and materials using standard semiconductor wafer technology. With micromechanical processes, such as anodic bonding of optical components and special solder bonding techniques, it is possible to realize complete hybrid integrated fiberoptic modules on silicon submount chips. These modules on silicon submount chips are fabricated as a part of a silicon wafer with the dimensions, tolerances and mechanical stability in the submicrometer region. With this technique we can use well-established low cost production methods on a wafer scale for active fiberoptic components. This means the complete fabrication, burn-in and testing procedures are practicable for example on a 5 in silicon-wafer. This allows the main module-functions to be separated from the cost intensive packaging efforts. It also provides a standard-submount base-component which can be used to develop a fiberoptic product-family for different applications with adapted packages. This means that these module-subcomponents can be produced in high volume production with low cost for high end fiberoptic components. Since all the essential optoelectrical and mechanical functions are combined in the highly stable subcomponent chip with minimal mechanical dimensions., the complete fiberoptic components can also provide the required reliability for these products. In some examples we propose appropriate exploitation's of these components for the realization of efficient fiberoptic transmission systems. One very important field for application of low cost components is the access network. Fiber to the Home needs medium datarates (up to 155 Mb/s) and medium length (up to 10 km). The technique described here allows optimum tradeoff between performance and cost for these applications. Using bidirectional transmission the cost for the bit transport can be reduced near to the level of copper lines. Therefore the German Telekom has installed a lot of subscriber lines using modules for bidirectional optical transmission.