Abstract

Glass has been used as the substrate for a wide range of passive, active, and nonlinear optical components. Passive functions, from beam splitting to wavelength multiplexing, have been performed in planar glass guides formed by ion-exchange or by the more recently developed silica-on-silicon technology. Although glass is typically viewed as a purely passive medium, it is possible to use glass waveguides to perform many active functions. For example, thermally induced changes in refractive index can be used to tune or switch components; response times as short as a few milliseconds are achievable. Active components can also be made by combining the glass guides with overlayers of active materials, such as liquid crystals or semiconductors. The recently demonstrated grafting of thin semiconductor layers onto glass guides has made it possible to combine the desirable qualities of glass and semiconductors. By such grafting, detectors have been integrated with glass waveguides, and the integration of sources with glass waveguides may be possible in the future. The use of rare-earth-doped glass provides another way to integrate lasers with glass waveguides. Finally, the extremely low absorption losses of glass guides makes them suitable for demonstration of nonlinear optical switching. My presentation reviews these and other uses for glass waveguides.

© 1990 Optical Society of America