USA As Represented by Secretary of the Navy

William E Martin

Paul S Catano

Larry B Stotts

An improved optical element is provided by an arrangement of optical wavedes disposed with two photoconductive paths and a plurality of electrodes arranged to impress an electric field across the optical waveguide configuration and the photoconductive paths. Optical energy is fed into an input optical waveguide and, dependent upon the optical inputs to the first and second photoconductive paths, an output is produced by the optical waveguide configuration in the manner of a logic gate. Variant configuration of the optical waveguide assembly can be made to perform in the manner of an AND gate, and OR gate, an exclusive OR gate, a NOR gate, or a NAND gate; alternatively, combination configurations can simultaneously perform multiple logic functions.

Optical logic elements

A miniature optical lens for coupling is fabricated from selected high rective index semiconductor material of uniform thickness. Refractive index gradients are generated in the semiconductor material through changes in composition developed under controlled conditions producing a desired focal length for determinable wavelengths of light energy emitted from a light source to which the miniature optical lens is coupled. The miniature optical lens thus fabricated is especially efficient for coupling light energy from light emitting diodes and junction lasers as well as in semiconductor micro-optics within the visible and the infrared wavelengths as well because the index of refraction of the lens material may be closely matched to the index of refraction of the light source, minimizing light energy transfer losses.

Method of making miniature coupling lens

An optical waveguide arrangement operates in the manner of an interferometer to provide modulator and/or switching functions. Two optical waveguide branches having a common connection diverge along a substantially coextensive distance and reconverge to provide first and second light paths of identical optical length. Conductive electrodes are disposed contiguous to at least one of the optical waveguide branches and are connectable through a controlling switch to a source of electrical energy for producing an electric field across the energized electrodes. In the absence of such electric field, light energy entering the two optical waveguide branches will propagate along identical optical path lengths and recombine constructively at the reconvergence of the waveguide branches. However, a selectively applied electrical energy changes the optical property of at least one of the optical waveguide branches causing phase differences in the optical energy transmitted by the branches and producing destructive interference at the reconvergence of the optical waveguide branches. The addition of two optical waveguide sections having different dimensions provides a switch function when one of such additional waveguides is dimensioned to be conducive to the propagation of first order mode light energy while the other waveguide is dimensioned to be conducive to the propagation of second order mode light energy.

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San Diego, CA, United States of America

William E Martin