Abstract: A method and apparatus for determining the surface orientation of objects in a field of view is provided by utilizing optical polarizers and photodetector arrays. Using the disclosed imaging technique, the polarization states of light can be determined over a two-dimensional distribution corresponding to the field of view. The polarization state at each pixel is correlated with the surface orientation of the corresponding object point. This method and apparatus is suitable for the recognition of three-dimensional objects in robot vision.

Abstract: A Fabry-Perot etalon is utilized as an optical switch for controllably switching an input optical signal on an input optical conduit between first and second output optical conduits. The etalon is comprised of a cavity formed by plane parallel periodic multilayer reflective surfaces with a variable index of refraction semiconductor medium sandwiched therebetween. The medium and periodic multilayer structures comprise, for example, Aluminum Gallium Arsenide. An optical pump injects an optical control beam into the medium to vary the index of refraction of the medium so as to cause the input optical signal to either be reflected from the cavity into the first output conduit or transmitted through the cavity to the second output conduit. Alternatively, electric fields, thermal fields, or injected carriers can be applied to the medium to vary the index of refraction thereof, thereby effecting the optical switching action.

Abstract: A light emitting diode circuit with an emitter coupled logic (ECL) interface is provided with temperature compensation by a series circuit consisting of a pair of resistors which are separated by at least one diode. A first switching field-effect-transistor which receives the output of the interface has its drain-to-source path coupled to the junction of one of the resistors and the diodes, while an output drive field-effect-transistor has its gate coupled to the junction of the other resistor and the diodes and its drain-to-source path coupled in series with a light emitting diode (LED).