Abstract: A pair of transparent trapezoidal prisms each having angled endfaces with the larger bases in juxtaposition with respect to each other forming an interface therebetween are provided with at least one optical input and output coupled to the angled endfaces of the prisms. Optical radiation is applied to the input and normal to the angled endface at an angle greater than the critical angle with respect to the interface between the prisms. A liquid crystal beam splitter is positioned in the interface for splitting the radiation between the prisms each of which has a liquid crystal optical shutter positioned in the respective prisms to receive optical radiation which has been transmitted or reflected from the beam splitter at an angle normal to the optical shutter. Each of the shutters is provided with a variable biasing voltage of a continuous nature which is selectively variable for controlling the radiation passing therethrough thereby forming a controllable optical switch.

Abstract: A photovoltaic semiconductor junction device which is particularly useful as a solar cell comprises a first layer of organic semiconductor material exhibiting one type of electronic conductivity and a second of inorganic semiconductor material having the same or opposite type conductivity. The first layer of organic semiconductor material has an energy bandgap relatively wider than that of the second layer of semiconductor material. The electron affinities of the first and second layers of semiconducting material may be equal, greater, or less than those of the other.The first layer of organic semiconductor material must either be doped to have a resistivity below 10.sup.6 ohm-centimeters or be sufficiently thin to allow conduction. In devices employing n-type layers on p-type substrates, the conduction band energy level of the organic material is preferably at substantially the same energy level as the conduction band energy level of the narrower band gap semiconductor material.