Abstract: Systems for enhancing the sensitivity of detecting an optical signal using nonlinear optics and method of performing the same. In one embodiment, a single-photon detection system includes an optical amplifier realized in a waveguide, and a photodetector coupled to an output of the optical amplifier. A light detection and ranging system includes the optical amplifier coupled to an optical source and one photodetector. In another embodiment, a photodetection system includes a plurality of optical frequency converters, coupled to an optical source, that sequentially convert a wavelength of photons of the optical source to a final wavelength, and a single-photon photodetector coupled to the optical frequency converters to detect single photons produced by the optical source. In another embodiment, an optical sensor includes an optical pump, and a transducer including an optical ring cavity coupled to the optical pump and configured to utilize optical four-wave mixing to detect an external stimulus.

Abstract: Systems for enhancing the sensitivity of detecting an optical signal using nonlinear optics and method of performing the same. In one embodiment, a single-photon detection system includes an optical amplifier realized in a waveguide, and a photodetector coupled to an output of the optical amplifier. A light detection and ranging system includes the optical amplifier coupled to an optical source and one photodetector. In another embodiment, a photodetection system includes a plurality of optical frequency converters, coupled to an optical source, that sequentially convert a wavelength of photons of the optical source to a final wavelength, and a single-photon photodetector coupled to the optical frequency converters to detect single photons produced by the optical source. In another embodiment, an optical sensor includes an optical pump, and a transducer including an optical ring cavity coupled to the optical pump and configured to utilize optical four-wave mixing to detect an external stimulus.

Abstract: Systems for enhancing the sensitivity of detecting an optical signal using nonlinear optics and method of performing the same. In one embodiment, a single-photon detection system includes an optical amplifier realized in a waveguide, and a photodetector coupled to an output of the optical amplifier. A light detection and ranging system includes the optical amplifier coupled to an optical source and one photodetector. In another embodiment, a photodetection system includes a plurality of optical frequency converters, coupled to an optical source, that sequentially convert a wavelength of photons of the optical source to a final wavelength, and a single-photon photodetector coupled to the optical frequency converters to detect single photons produced by the optical source. In another embodiment, an optical sensor includes an optical pump, and a transducer including an optical ring cavity coupled to the optical pump and configured to utilize optical four-wave mixing to detect an external stimulus.

Abstract: A directional notch filter for simultaneous transmit and receive of wideband signals comprises an antenna, an antenna match, a receiver, a power combiner, a first directional coupler, a second directional coupler and a shaping filter accepting a signal and producing a compensation signal as a replica of an antenna reflection transfer function, wherein the first and second directional couplers produce signals and portions of signals received by the antenna and sent to the receiver via the power combiner. The receiver can produce a receiver signal and the first directional coupler can produce a first signal as a portion of an overall signal received by the antenna, the first signal comprising at least reflection of a signal from the power amplifier and the second directional coupler samples a small portion of the receiver signal, said second directional coupler producing a second signal.

Abstract: Systems and methods for improved photonically-assisted RF filtering. Presently, processing of wide-band RF signals involves the use of multiple specialized equipment to isolate a region of interest from the spectrum. The present invention discloses the use of a modulation system to upconvert the RF signal onto the sideband of a light source such as a laser, an optical filter sub-system comprising a plurality of filtering units that function as combinations of IIR and FIR filters, and a resonant channelizing filter for noise reduction and rejection of undesired channels, and means for control and agility of a piecewise coherent optical filter. The resulting filtered RF signal may then be downconverted to the electrical domain for further signal processing.

Abstract: A directional notch filter for simultaneous transmit and receive of wideband signals comprises an antenna, an antenna match, a receiver, a power combiner, a first directional coupler, a second directional coupler and a shaping filter accepting a signal and producing a compensation signal as a replica of an antenna reflection transfer function, wherein the first and second directional couplers produce signals and portions of signals received by the antenna and sent to the receiver via the power combiner. The receiver can produce a receiver signal and the first directional coupler can produce a first signal as a portion of an overall signal received by the antenna, the first signal comprising at least reflection of a signal from the power amplifier and the second directional coupler samples a small portion of the receiver signal, said second directional coupler producing a second signal.

Abstract: Systems and methods for improved photonically-assisted RF filtering. Presently, processing of wide-band RF signals involves the use of multiple specialized equipment to isolate a region of interest from the spectrum. The present invention discloses the use of a modulation system to upconvert the RF signal onto the sideband of a light source such as a laser, an optical filter sub-system comprising a plurality of filtering units that function as combinations of IIR and FIR filters, and a resonant channelizing filter for noise reduction and rejection of undesired channels, and means for control and agility of a piecewise coherent optical filter. The resulting filtered RF signal may then be downconverted to the electrical domain for further signal processing.

Abstract: Both link-level and path-level performance monitoring is obtained in any point of a multi-link network where transmitting points in the network are adapted to transmit codes only from a subset of the codes that receiving points in the network are adapted to receive, with one of the codes that transmitting points are adapted to transmit being chosen to represent an error-reporting code, and substituting, at monitoring points, any received code that is not one of the codes in the subset with the error-reporting code. By measuring the number of received codes that are in error, a link-level error measure is obtained, and by measuring the number of error-reporting codes, a path-level measure is obtained.