Abstract: A silicon oxynitride (SiON)/silicon dioxide (SiO2) optical waveguide switch with a wavelength locked feedback control loop which monitors the wavelength of UV radiation produced by a UV tunable laser diffraction grating write source which has passed through a UV bandpass filter and is then used to selectively write a diffraction grating in the optical waveguide switch. The diffraction grating structure can be switched on or off at will, resulting in an optical switch element for IR radiation traveling through the optical waveguide. This optical switch element is a basic building block which can be used for many other systems, such as optical logic gates or all-optical cross connect switches for wide area networks. Further, it may be used to selectively tap off a portion of the optical signal, for example to read header information in a data stream (or packets) which indicates the destination switch port of the optical data, without disrupting the remaining optical data.

Abstract: Electrically switchable optical elements, such as application specific integrated elements including filters, lenses and switches, are combined with wavelength locked feedback loops. Electrically Switchable Bragg Grating (ESBG) technology is combined with a wavelength locked feedback loop to provide variable focal length optical systems which automatically adjust the focal length of incident light.