Abstract: The present invention is an efficient method for the fabrication of three-dimensional structures in GaAs-based materials. The method is particularly suitable for the realization of 3D photonic crystals. The method relies on the observation that the oxidation rate of Ga1-xA1xAs in water-vapor atmosphere is a strong function of the aluminum content in the alloy. Thus, a stack of Ga1-xA1xAs layers with varying concentration of A1 is grown on GaAs substrate. The top surface is patterned with an array of holes, which are then transferred to the underlying layers by dry etching. Subjecting the so-prepared structure to oxidation in water vapor atmosphere at an elevated temperature results in lateral oxidation of the material exposed by the etched holes. The lateral oxidation depth depends on aluminum content in a particular layer. The oxide is then removed by an aqueous solution of hydrofluoric acid and a three-dimensional array of voids ensues.

Abstract: A method for generating images in polymers comprising: preparing a template with an extruding desired pattern; contacting a surface of a polymer with a desired pattern of the extruded surface of the template; treating the surface of the polymer with at least one of a liquid acid and vapor; treating the surface of the polymer with a high temperature for crosslinking; separating the template and polymer and revealing an acid imprint of the desired pattern on the surface of the polymer; baking the polymer to drive diffusion of the acid; and developing the polymer with at least one of a wet and dry process to produce a negative pattern in the polymer.

Abstract: A method for manufacturing optical components in a three-dimensional photonic crystal lattice. A first resist (9) is coated on a substrate (10) and exposed to an e-beam (11), to produce an imaged area (12). Another resist coating is applied to thicken the resist (13) and an interference exposure (15) is used to image the result. This is developed to form periodic voids (16), which may be filled with a materials having a high refractive index to form a pattern (18 and 12) when the resist (13) is removed.

Abstract: A process for making photonic crystal circuit and a photonic crystal circuit consisting of regularly-distributed holes in a high index dielectric material, and controllably-placed defects within this lattice, creating waveguides, cavities, etc. for photonic devices. The process is based upon the discovery that some positive ultraviolet (UV) photoresists are electron beam sensitive and behave like negative electron beam photoresists. This permits creation of photonic crystal circuits using a combination of electron beam and UV exposures. As a result, the process combines the best features of the two exposure methods: the high speed of UV exposure and the high resolution and control of the electron beam exposure. The process also eliminates the need for expensive photomasks.

Abstract: A planar photonic bandgap structure includes a substrate and a suspended membrane with holes. A waveguiding film is applied directly on and registered with the membrane so as to avoid the holes. The film has an index of refraction which is higher than an index of refraction of the membrane to allow a waveguiding function to occur within the film. A method of forming a planar photonic bandgap structure includes applying first and second films on a substrate and exposing a pattern of a plurality of holes on the second film. The exposed pattern is developed using a solvent where the dissolution rate of the first film is greater than a dissolution rate of the second film. A waveguiding layer is applied onto a top surface of a suspended membrane such that the layer has an index of refraction greater than an index of refraction of the suspended membrane.

Abstract: The invention is a compact optical gyroscope based on the Sagnac effect that combines a micro-ring cavity laser comprising a magneto-optical material and a magnetic field to circumvent the lock-in phenomenon at low rates of rotation. The invention also embodies novel processes for breaking lock-in using a transverse Faraday effect.

Abstract: The invention is a compact optical gyroscope based on the Sagnac effect that combines a micro-ring cavity laser comprising a magneto-optical material and a magnetic field to circumvent the lock-in phenomenon at low rates of rotation. The invention also embodies novel processes for breaking lock-in using a transverse Faraday effect.

Abstract: A simple foot operated mechanism for controlling both throttle and brakes of a motor vehicle is disclosed. The throttle is controlled by pivoting foot at the ankle. A locking mechanism is used, which provides rigid support for the driver's foot while operating the throttle. The brakes are applied by pushing the heel down to release the locking mechanism, and straightening the knee. The leg movement from accelerating to braking is a natural and smooth one, and in a natural way cuts the fuel to the engine before brakes are applied. Once brakes are applied it is possible to open the throttle valve without necessarily releasing brakes.