Thin phase selective transparent detector for length measurements

Abstract Thin transparent nanosensors are the pivotal element of a new standing wave interferometer for length measurement. The three-terminal based nanosensor consists of two thin pin-photodiodes of amorphous silicon which are embedded between three transparent contact layers of zinc oxide. The sensor provides two position dependent photocurrents when incorporated into an optical standing wave. These signals can be used for bi-directional fringe counting, a standard method for interferometrical length measurement. Since the i-layer has a significant influence on the device performance, nanosensors with optical absorber layer thicknesses of λ /4 and 3 λ /4 were realized. The optoelectronic properties of the sensors will be discussed.