Abstract: An optical system for coupling light from a monolithic waveguide chip from one optical path to another on different layers of the chip or into or out of the chip along an edge thereof by coupling a GRIN lens to the edge. Coupling a GRIN lens having a reflective end allows light to be launched out of and back into the waveguide chip. Alternatively a GRIN lens having a plurality of fibers coupled thereto can be used to couple signals carried by the fibers into the waveguide chip.

Abstract: A method of forming a grating in waveguide uses an ion exchange process to provide a waveguide region within and clad by a surrounding substrate and through an ion exchange process diffusing into the substrate an ion, such as such as Ag+, that is photosensitive and that provides a refractive index difference from adjacent non-diffused regions of the substrate. After the diffusion process, the step of exposing at least some of the waveguide region to light having a suitable intensity and duration to provide a permanent index change within regions of the waveguide region to form a grating is performed.

Abstract: A sensor for detecting substances including hydrocarbons includes an integrated optical interferometer in the form of a Mach-Zehnder interferometer having a measuring arm and a comparison arm in a wave guide substrate. A polymer such as polysiloxane is applied as a superstrate to the wave guide in the region of the measuring arm. This superstrate can be penetrated by the substance to be detected. Swelling response, gas absorption, refractive index of the polymer and doping with chromophores or fluorophores, layer thickness and layer length are all parameters which can be adapted for a substance-selective performance. Other means of selection include various superstrates on a number of interferometers mounted parallel on a chip and polychrome measurements in combination with methods of pattern recognition constitute further means of selection.