Abstract: A dual band detector includes a substrate, a composite barrier, a first absorber on the substrate and on a light incident side of the composite barrier, the first absorber for detecting first infrared light wavelengths, a second absorber on the composite barrier on a side opposite the light incident side, the second absorber for detecting second infrared light wavelengths, wherein a bandgap of the first absorber is larger than that of the second absorber, wherein the composite barrier includes a first secondary barrier, a primary barrier, and a second secondary barrier, wherein the first and second secondary barriers may have a lower bandgap energy than the primary barrier, wherein the first or the second secondary barrier may have a doping level and type different from that of the primary barrier, and wherein at least the primary barrier blocks majority carriers and allows minority carrier flow.

Abstract: Optical angle of arrival sensors and methods for determining an angle of arrival of incident light are provided, wherein one sensor includes a focusing lens and an array of lateral-effect position sensing detector (LEPSD) elements. The focusing lens is configured to focus light on the array, wherein each of the LEPSD elements includes an absorber region that absorbs light of a first wavelength range that is focused on the LEPSD elements. Each of the LEPSD elements further includes at least one lateral current conducting layer that has a relatively low sheet resistance.

Abstract: Optical angle of arrival sensors and methods for determining an angle of arrival of incident light are provided, wherein one sensor includes a focusing lens and an array of lateral-effect position sensing detector (LEPSD) elements. The focusing lens is configured to focus light on the array, wherein each of the LEPSD elements includes an absorber region that absorbs light of a first wavelength range that is focused on the LEPSD elements. Each of the LEPSD elements further includes at least one lateral current conducting layer that has a relatively low sheet resistance.

Abstract: A waveguide assembly for a use with, for example, a microwave receiver. The waveguide assembly includes: a waveguide; a tapered structure disposed within the waveguide, the tapered structure tapering in thickness from a first end with a zero height to a second end where the tapered structure has a height which nearly fills, but does not completely fill, the waveguide, to thereby define a modulator receiving space between the tapered structure and an adjacent wall of said waveguide. The second end of the tapered structure is preferably disposed adjacent an open circuited end of the waveguide. An electro-optic modulator is disposed on a dielectric substrate, the dielectric substrate being disposed at least partially within the modulator receiving space and the electro-optic modulator being disposed so that it is located, in use, at an antinode of a standing wave of the waveguide assembly.

Abstract: An infrared photo-detector with multiple discrete regions of a first absorber material. These regions may have geometric shapes with sloped sidewalls. The detector also may include a second absorber region comprising a second absorber material that absorbs light of a shorter wavelength than the light absorbed by the multiple discrete absorber regions of the first absorber material. The geometric shapes may extend only through the first absorber material. Alternatively, the geometric shapes may extend partially into the second absorber region. The detector has a metal reflector coupled to the multiple discrete absorber regions. The detector also has a substrate containing the discrete absorber regions and the second absorber region. The substrate can further include geometric shaped features etched into the substrate, with those features formed on the side of the substrate opposite the side containing the discrete absorber regions and the second absorber region.

Abstract: An absorber is disclosed. The disclosed absorber contains a base layer, and a plurality of pillars disposed above the base layer and composed of material configured to absorb an incident light and generate minority electrical carriers and majority electrical carrier, wherein the height of the pillars is predetermined to provide a common pyramidal outline shared by the pillars in the plurality of pillars.

Abstract: A spread spectrum waveform generator has a photonic oscillator and an optical heterodyne synthesizer. The photonic oscillator is a multi-tone optical comb generator for generating a series of RF comb lines on an optical carrier. The optical heterodyne synthesizer includes first and second phase-locked lasers, where the first laser feeds the multi-tone optical comb generator and the second laser is a single tone laser whose output light provides a frequency translation reference. At least one photodetector is provided for heterodyning the frequency translation reference with the optical output of the photonic oscillator to generate a spread spectrum waveform. A receiver pre-processor may be provided to operate on the spread spectrum waveform.

Abstract: A waveguide of radio frequency electromagnetic fields is multi-furcated into a plurality of radio frequency waveguide sections, each radio frequency waveguide section having an optoelectronic modulator electrically coupled to it. Each optoelectronic modulator has an optical waveguide disposed therein such that, in use, light traveling in the optical waveguides of the optoelectronic modulators travels in a direction orthogonal with respect to the direction the radio frequency electromagnetic field travels in the radio frequency waveguide sections. The plurality of radio frequency waveguide sections are fed from a common source of said radio frequency energy.

Abstract: The present invention describes a microresonator that can be used as a 1:f variable coupler in a unit cell. It is described how a cascade of unit cells can be used to form a tunable, higher-order RF-filter with reconfigurable passbands. The disclosed filter structure can be utilized for the narrowband channelization of RF signals that have been modulated onto optical carriers. It is also disclosed how to utilize add/drop capabilities of the contemplated microdisks to confer connectivity and cascading in two dimensions. The present invention can conveniently provide a wavelength division multiplexing router, where an array of unit cells as provided herein can form a programmable optical switching matrix, through electronic programming of filter parameters.

Abstract: The invention is a Demodulator for an Optical Analog Pulse Position Modulated signal suitable for inclusion in receivers for Free Space Optical communication systems. In one embodiment the Demodulator may use the pulse position modulated optical information signal and the clock signal with different wavelengths. By proper biasing of a Semiconductor Optical Amplifier and selection of wavelengths for the information signal and the clock signal, the performance of the Demodulator is made insensitive to noise in the received signals.

Abstract: The invention is an optical labeling/identification system that comprises an optical interrogator, optical label and a programmer. The optical label stores and returns to the interrogator different parts of a wavelength code word. The programmer programs the optical labels with a programming light beam to change the wavelength response of the labels. Interrogation and programming of the labels can be accomplished from a stand off distance without physical contact between the label and the interrogator/programmer. The label may be applied to uneven, wrinkled or discontinuous surfaces.

Abstract: A spread spectrum waveform generator has a photonic oscillator and an optical heterodyne synthesizer. The photonic oscillator is a multi-tone optical comb generator for generating a series of RF comb lines on an optical carrier. The optical heterodyne synthesizer includes first and second phase-locked lasers, where the first laser feeds the multi-tone optical comb generator and the second laser is a single tone laser whose output light provides a frequency translation reference. At least one photodetector is provided for heterodyning the frequency translation reference with the optical output of the photonic oscillator to generate a spread spectrum waveform. A receiver pre-processor may be provided to operate on the spread spectrum waveform.

Abstract: The present invention is a programmable and latching retro-reflective construct suitable for use as an optical label in an optical labeling system. The invention contains retro-reflective structures such as lens beads, corner cubes or other retro-reflecting type structures. The retro-reflective construct further comprises a wavelength selective, programmable and latching reflecting structure located at the reflecting surfaces of the retro-reflective structures. The optical construct can optionally contain additional optical filtering structures. Methods for fabricating the invention are also described.

Abstract: A PPM transmitter includes an optical clock generator for generating equally-spaced optical pulses with a sampling period T; an encoder for transforming an incoming waveform U(t) into a linear combination V(t) of U(t) and a delayed output V(t?kT) according to a rule V(t)=U(t)+aV(t?kT), where k is a positive integer, V(t) is voltage generated by the encoder and a is a coefficient; and an optical delay generator for delaying optical pulses generated by the optical clock generator in proportion to the voltage V(t), such that ?tn=bV(t), where b is another coefficient and where ?tn is the amount of delay imposed by the optical delay generator. The PPM transmitter functions with a PPM receiver for communicating data without the need to transmit or otherwise provide a clock signal. The PPM receiver decodes an original series of the delayed optical pulses Q(t) and a second series Q(t?ckT) delayed by ckT where c is a coefficient.

Abstract: The present invention describes a microresonator that can be used as a 1:f variable coupler in a unit cell. It is described how a cascade of unit cells can be used to form a tunable, higher-order RF-filter with reconfigurable passbands. The disclosed filter structure can be utilized for the narrowband channelization of RF signals that have been modulated onto optical carriers. It is also disclosed how to utilize add/drop capabilities of the contemplated microdisks to confer connectivity and cascading in two dimensions. The present invention can conveniently provide a wavelength division multiplexing router, where an array of unit cells as provided herein can form a programmable optical switching matrix, through electronic programming of filter parameters.

Abstract: The present invention is a programmable and latching retro-reflective construct suitable for use as an optical label in an optical labeling system. The invention contains retro-reflective structures such as lens beads, corner cubes or other retro-reflecting type structures. The retro-reflective construct further comprises a wavelength selective, programmable and latching reflecting structure located at the reflecting surfaces of the retro-reflective structures. The optical construct can optionally contain additional optical filtering structures. Methods for fabricating the invention are also described.

Abstract: A system and method for generating electrical power from a heat source utilizing both photonic and thermal conversion are disclosed. Specifically, power is generated by coupling photon converters to thermoelectric pairs in a way such that the thermoelectric pairs gain not only the charge carriers (holes and electrons) generated by the photons absorbed by the photon converters, but also the charge carriers generated by excess heat in the photon converters and an added thermal gradient generated by excess energy in the absorbed photons. Heat exchanger variations for such a system are also disclosed. Specifically, heat exchangers with and without photon emitters are disclosed and variants of refractive indices for heat exchanger systems are disclosed.

Abstract: The present invention is a programmable and latching retro-reflective construct suitable for use as an optical label in an optical labeling system. The invention contains retro-reflective structures such as lens beads, corner cubes or other retro-reflecting type structures. The retro-reflective construct further comprises a wavelength selective, programmable and latching reflecting structure located at the reflecting surfaces of the retro-reflective structures. The optical construct can optionally contain additional optical filtering structures. Methods for fabricating the invention are also described.

Abstract: This invention provides a versatile unit cell as well as programmable and reconfigurable optical signal processors (such as optical-domain RF filters) that are constructed from arrays of those unit cells interconnected by optical waveguides. Each unit cell comprises an optical microdisk, an optical phase shifter, and at least one input/output optical waveguide, wherein the microdisk and the phase shifter are both optically connected to a common waveguide.

Abstract: An RF photonic link having at least one light source, at least one photodetector, multiple optoelectronic modulators, and an RF waveguide common to each one of said multiple optoelectronic modulators. The multiple optoelectronic modulators are optically arranged in parallel to receive light from said at least one light source and are disposed in said RF waveguide. The RF waveguide, in use, guides an RF electromagnetic field applied to each of the multiple optoelectronic modulators disposed therein, the RF electromagnetic field propagating through the RF waveguide in a direction that is perpendicular to a direction in which an optical field propagates through each of said optoelectronic modulators.