Abstract: Silicon photodetectors using near-infrared dipole antennas. The photodetectors include a silicon region formed on a semiconductor substrate, dipole antenna forming two arms that are spaced apart with the silicon region therebetween and inducing an electromagnetic wave signal of incident light, and electrodes disposed in a vertical direction of the dipole antenna and spaced apart with the silicon region therebetween, where a critical bias voltage is applied to the electrodes to induce an avalanche gain operation in the silicon region.

Abstract: Silicon photodetectors using near-infrared dipole antennas. The photodetectors include a silicon region formed on a semiconductor substrate, dipole antenna forming two arms that are spaced apart with the silicon region therebetween and inducing an electromagnetic wave signal of incident light, and electrodes disposed in a vertical direction of the dipole antenna and spaced apart with the silicon region therebetween, where a critical bias voltage is applied to the electrodes to induce an avalanche gain operation in the silicon region.

Abstract: Methods in accordance with the present invention provide a quasi-planarized surface between one or more semiconductor devices and at least a portion of surrounding passivation material, where the devices have different elevations above a substrate. A hard mask defines the planarized surface as the interface between the hard mask and both the passivation layer and the device, after a passivation layer etching process. The resulting planarized surface has a small to zero step height, is insensitive to passivation layer non-uniformity and etch non-uniformity, provides full passivation of the device side wall, provides protection for the device against etch-induced damage, and prevents the detrimental effects of passivation layer voids.

Abstract: Methods in accordance with the present invention provide a quasi-planarized surface between one or more semiconductor devices and at least a portion of surrounding passivation material, where the devices have different elevations above a substrate. A hard mask defines the planarized surface as the interface between the hard mask and both the passivation layer and the device, after a passivation layer etching process. The resulting planarized surface has a small to zero step height, is insensitive to passivation layer non-uniformity and etch non-uniformity, provides full passivation of the device side wall, provides protection for the device against etch-induced damage, and prevents the detrimental effects of passivation layer voids.

Abstract: A method for designing an integrated circuit having optical inputs and outputs includes the step of selecting an integrated circuit design which includes at least one circuit cell design for processing electric signals. The circuit cell design has a predetermined number of electric inputs and electric outputs. The integrated circuit design also includes a plurality of layers of metalization for providing electric coupling. After the electronic integrated circuit design is selected, a predetermined number of optical input devices are located on the circuit cell design in a first prearranged orientation. The predetermined number of optical input devices is no greater than the predetermined number of electric inputs to the circuit cell. Also after the electronic circuit design is selected, a predetermined number of optical output devices are located on the circuit cell design in a second prearranged orientation.

Abstract: A single fiber communication system which uses a short pulse light source in conjunction with a short pulse detector. The short pulse source transmits a short pulse carrier signal that is passed down an optical fiber to a reflective modulator. The reflective modulator imparts a modulation to the carrier and reflects it back up the fiber where it is detected by the short pulse light detector. Through the use of short pulses the invention is able to overcome the problem of fiber reflection. The reflected modulated pulse is easily separated from the undesired reflections from the fiber, thereby eliminating noise in the detected signal and increasing the effectiveness of the single fiber system.

Abstract: A tunable laser whose lasing frequency can be changed by varying the absorbance of absorber layers that are preceding a standing wave of the laser cavity. Changes in the absorbance of the layers are accomplished by varying the strength of the absorber layers through application of voltage to the layers.

Abstract: An optical signal attenuation device and associated method for selectively attenuating the signal strengths of different wavelength signals contained within a multiplexed optical transmission. The attenuation device includes a diffracting element that diffracts the multiplexed optical system and directs the different wavelength signals onto separate optical paths. A modulator array is provided that contains a plurality of optical modulators spaced at a pitch so that each modulator receives one of the different wavelength signals. Each optical modulator causes a signal to be produced that correspond to the signal it receives, except that the signal strength of the emitted signal is altered to fall within a desired range. Each signal emitted by the optical modulators is again directed toward a diffraction element. The diffraction element combines the separate wavelength signals, thereby producing a multiplexed signal where each wavelength has a signal strength that falls within a common range.

Abstract: Optical analog information processing capability is achieved by providing a SEED device configured to operate in a differential mode. This "differential SEED" utilizes pairs of input signal beams to represent bipolar analog data and to process those data in a linear fashion. The difference in the optical powers of the input signal beams is used to modulate the absorption of power supply beams in quantum well diodes, such that the difference in the absorbed powers in the quantum well diodes is proportional to the difference in the powers of the input signal beams. The differential SEED can be configured to perform various image processing operations on bipolar analog data, including, for example, image addition and subtraction, optical multiplication, and evaluating spatial derivatives.