Abstract: A lateral-effect position-sensing detector includes a second lateral-current collector layer, an electron barrier layer on the second lateral-current collector layer, an absorber layer on the electron barrier layer, a first lateral-current collector layer on the absorber layer, and a first elongate electrical contact and a second elongate electrical contact on each of the lateral-current collector layers. Incident light radiates a transparent first lateral-current collector layer to be absorbed by the undepleted absorber layer where electron and holes are generated. The depleted electron barrier layer prevents a flow of electrons from the absorber layer to the second lateral-current collector layer but allows electrons to flow to the second lateral-current collector layer. The lateral-effect position-sensing detector is sensitive to a lateral position between the first elongate electrical contact and the second elongate electrical contact of incident light on each of the lateral-current collector layer.

Abstract: Several embodiments of a system and method of an optical-frequency (OF) synthesizer are disclosed that produces an optical frequency (OF) tone derived from a dispersive resonator and phase-locking to a radio frequency (RF) tone to achieve high precision. Thus, the stability of the synthesized OF tone is related to the stability of the RF tone. A frequency control word provides for a wide range of programmability to the frequency of the output OF tone. The OF synthesizer establishes the absolute value of the optical frequency of its output tone by making use of a dispersive optical resonator and applying appropriate corrections obtained dynamically by interrogating the comb lines. The reference resonator defines a semi-dormant OF reference comb, wherein the lines of that reference comb are associated with the modes of the reference resonator. Several selected modes of this reference resonator are interrogated by locking the frequency of light emitted by lasers to those resonator modes.

Abstract: Systems and methods for a multi-band position sensor and a multi-band optical detector are disclosed. This system comprises a dual-axis, lateral-effect position sensor for locating spots of light that has energy in two wavelength bands. This sensor senses the time-varying intensities of the light in each of the two wavelength bands. This sensor also provides the location of the spot of light on the light-detecting plane of the sensor. Examples are provided for light of two mid-wave infrared (MWIR) wavelength bands or of a short-wave infrared (SWIR) and a MWIR band. This sensor approach, could be applied to detect light of other wavelength bands, such as a combination of a MWIR and a long-wave infrared (LWIR) band. This concept is extended to an array of detectors for multi-band optical detection and multi-source location and tracking. Monolithic chip level fabrication of the multi-band detectors is also discussed.

Abstract: A sensor includes a plurality of transmitter units, a photodetector, and an optical system coupled to the plurality of transmitter units and the photodetector. Each of the transmitter units simultaneously transmits a light beam having a plurality of wavelengths, the optical system directs the light beam from each of the transmitter units onto a same illuminated spot on a probed surface, and the optical system collects light from the same illuminated spot and directs the light to the photodetector.

Abstract: A radio frequency (RF) link includes a link transmitter that includes a data modulator for modulating a data waveform together with an RF carrier, a photonic encoder coupled to the data modulator, and a transmitter antenna for transmitting an RF signal, wherein the RF signal comprises an output of the photonic encoder, and a link receiver including a receiver antenna for receiving the RF signal, a first laser source, a photonic limiter coupled to the first laser source and to the receiving antenna, a photonic decoder coupled to the photonic limiter, a photo-receiver coupled to the photonic decoder, and a demodulator coupled to the photo-receiver for demodulating an output of the photo-receiver with the RF carrier to form a data output.

Abstract: A system and method includes an array position sensing detector. The array position sensing detector includes a lateral effect position sensing detector element and a summing amplifier. The lateral effect position sensing detector element produces an output coupled with the summing amplifier through a switch.

Abstract: A photonic waveguide for conducting light having first and second wavelengths, the waveguide comprising superposed first and second strips of light conducting semiconductor materials having first and second refractive indexes, wherein the second wavelength is shorter than the first wavelength and the second refractive index is higher than the first refractive index, wherein the width and height of the first strip of light conducting semiconductor material are such that the first strip of light conducting semiconductor material is adapted to confine an optical mode of the first wavelength and the width and height of the second strip of light conducting semiconductor material are such that the second strip of light conducting semiconductor material is adapted to confine an optical mode of the second wavelength but is too narrow to confine an optical mode of the first wavelength.

Abstract: A wavelength-selective optical diffuser comprising a substrate of a first material having opposite first and second surfaces, wherein said first material is transparent to a first wavelength ?S and a second wavelength ?L, with ?L>4?S; at least a first surface of said substrate having a surface relief such that a beam of light having the first wavelength ?S is diffused, with a rms phase delay S>?/4, when traversing said substrate; and a beam of light having the second wavelength ?L is minimally diffused, with a rms phase delay S<?/4, when traversing said substrate.

Abstract: An electro-optic modulation structure comprises a first electrode and a second electrode and a first electro-optic strip; wherein the first electrode has a slab portion and a first ridge protruding from the slab portion of the first electrode, and the second electrode has a slab portion and a first ridge protruding from the slab portion of the second electrode, the first protruding ridge of the first electrode and the first protruding ridge of the second electrode being disposed on opposite sides of the first electro-optic strip and both protruding ridges abut the first electro-optic strip.

Abstract: A two-dimensional phased array beam former comprising at least first and second chips having each top and bottom surfaces, the bottom surface of the first chip being attached to the top surface of the second chip; the first and second chips having each an emitter side surface, the emitter side surfaces of the first and second chips facing a same direction and comprising each a plurality of emitters; wherein each of said first and second chips comprises at least one conductive post extending between said top and bottom surfaces; the at least one conductive post of the first chip being vertically aligned with and connected to the at least one conductive post of the second chip.

Abstract: A phased array that comprises a predetermined number of emitter/receiver elements; said emitter/receiver elements being arranged on a array formed of stacked rows, wherein the emitter/receiver elements in each row of the array are distributed according to a pseudo-random pattern; and the heights of the rows vary according to a pseudo-random pattern.

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 infrared photo-detector array and a method for manufacturing it are disclosed. The infrared photo-detector array contains a collector layer, a first absorber layer that absorbs incident light of a first wavelength band and generates first electrons and first holes, a second absorber layer that absorbs incident light of a second wavelength band and generates second electrons and second holes, and wherein the wavelengths of the incident light in the first wavelength band are shorter than the wavelengths of the incident light in the second wavelength band, and wherein the second absorber layer is laterally contiguous across at least two photo-detectors. The method disclosed teaches how to manufacture the infrared photo-detector array.

Abstract: A position sensitive detector includes a substrate, an absorber layer on the substrate, a barrier layer on the absorber layer, a contact layer on the barrier layer, and a first contact and a second contact on the contact layer. The barrier layer prevents a flow of majority carriers from the absorber layer to the contact layer. The position sensitive detector is sensitive to a lateral position between the first contact and the second contact of incident light on the contact layer.

Abstract: An optical-waveguide grating modulator is compatible with high-frequency electrical modulation signals of limited bandwidth. The modulator comprises an optical grating formed in an optical waveguide constructed from electro-optic (EO) material and an electrode that is an RF waveguide or RF transmission line that conducts a traveling-wave electromagnetic (EM) field and that contains a portion of the optical-grating waveguide with a continuous grating. The RF input modulation signal is coupled into an RF EM field that propagates through the RF waveguide or transmission line in a direction that is parallel to the direction the light propagates in the optical-grating waveguide and that EM field overlaps the optical-grating waveguide. The light travels along the optical-grating waveguide preferably at the same velocity as the RF EM field travels along the RF waveguide or transmission line.

Abstract: An optical modulator includes a waveguide Mach-Zehnder interferometer having a first and a second input and a first and a second output, a feedback waveguide segment connecting the second output with the second input, and a traveling-wave electrode; wherein the Mach-Zehnder interferometer, feedback waveguide segment and traveling-wave electrode are substantially arranged at or adjacent the perimeter of a smooth curve defining a closed geometric figure, the traveling-wave electrode extending along at least 50% of the length of the perimeter of the smooth curve.

Abstract: Centroid locating sensors and methods for locating an illuminated spot on a detector are provided. One sensor includes a plurality of photo-diode (PD) detector elements connected to the PD detector elements. The sensor also includes a plurality of digitization comparators connected to the plurality of PD detector elements and configured to receive output signals from the plurality of PD detector elements and generate a binary 1 output when the output from the PD detector element exceeds a threshold set point and generate a binary 0 output when the output is below the threshold set point. The sensor further includes a plurality of spatial filtering logic circuits connected to the digitization comparators and are configured to receive outputs from a plurality of the PD detector elements and to reject noise for one of the PD detector elements.

Abstract: A system and method includes an array position sensing detector. The array position sensing detector includes a lateral effect position sensing detector element and a summing amplifier. The lateral effect position sensing detector element produces an output coupled with the summing amplifier through a switch.

Abstract: An photonic RF circulator is described that provides greater than 40 db of isolation between a Received RF signal and a Transmitted RF signal in a simultaneous transmit and receive device. The photonic RF circulator uses light modulated in an optical waveguide grating where the Received RF signal co-propagates with the light and the Transmitted RF signal counter-propagates with the light. Variations described within provide for broadening the bandwidth of the T/R isolation and rejection of various noise sources.

Abstract: Systems and methods for dual-mode optical sensing are provided. One system includes a focal-plane array (FPA) imaging detector configured to detect light of a first wavelength range and an illuminated-spot locating detector (ISLD) including an array of light-detecting elements configured to detect light of a second wavelength range, wherein the ISLD has a transparency to light of the first wavelength range. The system further includes a wavelength-selective optical diffuser configured to diffuse light of the second wavelength range, wherein the shortest wavelength of the first range is larger than the longest wavelength of the second range, the ISLD is positioned such that the light to be detected by the FPA imaging detector first passes through the ISLD, and the FPA imaging detector, the ISLD and the wavelength-selective diffuser share a common optical axis.