Abstract: Disclosed herein are techniques for bidirectional communication in a network, such as a cable television (CATV) system, for return band with echo cancellation. The techniques result in a minimum loss of available return bandwidth to facilitate forward out of band (OOB) communication to a client device, e.g., set top box (STB), within the extended return band, such as a return band extended beyond a frequency previously used for OOB communications.

Abstract: In an optical system having multiple cascaded splitter/combiners, a trunk port and/or a drop port is configured for at least one of the splitter/combiner units. Drop ports may be configured with an average gain control, and the trunk ports may be configured to have individual gain control to provide a more precise overall gain and to maintain adequate signal levels. Embodiments apply to evolving RFoG architectures designed to serve a large number of subscribers without suffering from OBI (Optical Beat Interference) by retransmitting an optical signal through cascading splitters/combiners.

Abstract: Systems and methods for relaying upstream signals received from a plurality of subscribers to a remote head end. Preferably, the systems and methods use a switch that selectively opens when upstream RF signals are not present and closes when upstream RF signals are present, in a manner that reduces noise.

Abstract: An active receiver structure that combines a large number of detectors without bandwidth penalty may provide a better signal-to-noise ratio (SNR) than conventional Radio Frequency over Glass (RFoG) networks. A transmission line receiver is used to combine a large number of optical detectors into a single radio frequency (RF) signal without a bandwidth penalty and a modest penalty in noise performance that results in an SNR that is much better than traditional optical combining techniques that are followed by a single detector. An optical multiplexer structure may be designed around the active splitter such that passive optical network (PON) operation is not impeded.

Abstract: A bi-directional optical transceiver includes multiple single mode optical ports and a multi-mode optical port. A multi-mode optical combiner combines single mode optical signals received at the single mode optical ports into a multi-mode optical signal at the multi-mode optical port. Each single mode optical signal has a distinct optical mode that does not interfere with the optical mode of the other single mode optical signals. A photo detector detects a total optical power of the plurality of single mode optical signals in the multi-mode optical signal. An amplifier is coupled to receive an output of the photo detector.

Abstract: Systems and methods that cancel distortion in the amplified outputs of a node by equalizing the distortion characteristics amplifiers in the node, so as to improve the effectiveness of predistortion applied to a downstream signal amplified by the node.

Abstract: Methods and systems for modulating an amplifier power supply to efficiently attain amplified RF output power with much lower power dissipation than existing amplifiers. In a cable television (CATV) network, a processor receives a signal to be amplified by an amplifier at a location remote from the processor. A bias point of the amplifier may be variably modulated based on peaks of an input signal to reduce amplifier dissipation.

Abstract: Systems and Methods for reducing distortion due to bursts of upstream transmission in an HFC CATV network. In some preferred systems, the functionality of an Optical Network Unit (ONU) may occur within a node or amplifier along a direction upstream from a subscriber's home.

Abstract: Systems and methods that cancel distortion in the amplified outputs of a node by equalizing the distortion characteristics amplifiers in the node, so as to improve the effectiveness of predistortion applied to a downstream signal amplified by the node.

Abstract: Systems and methods for amplifying signals. In some embodiments, the signals may be amplified using a diode steering network with an amplifier operated in class AB mode. In some embodiments, distortion in the amplified signal may be corrected using a feed forward cancellation circuit operated in class A mode.

Abstract: A remote node system with an amplitude modulation (AM) star architecture is formed between a remote node and a plurality of field nodes split from the remote CCAP node. In embodiments, an R-CCAP node can be combined with amplitude modulation (AM) optics in a star architecture for building low power nodes, supporting set top box (STB) out of band (OOB) signals, and increasing system bandwidth (BW). The remote node can be implemented in media content delivery networks, such as a hybrid fiber-coax HFC network or evolving radio frequency over glass (RFoG) networks.

Abstract: Platelets or blood cells are detected in a fluid sample by adjusting a focal depth of a microscope through a range of values, the microscope having a mounted sample and an objective lens adapted with one or both of (a) a spherical aberration correction unmatched to a utilized cover plate for the sample, or (2) a numerical aperture unmatched to a utilized illumination source for the sample. Images are recorded at different specific focal depths and in multiple z planes of a fluid bearing the platelets, where the position of platelets may overlap on different of the multiple z planes that are recorded, the images recorded through the cover plate, thus causing the generation of a specific light-dark pattern indicative of platelets at particular positions and at multiple depths in the fluid media. The images are analyzed for the specific light-dark pattern.

Abstract: Methods and systems for modulating an amplifier power supply to efficiently attain amplified RF output power with much lower power dissipation than existing amplifiers. In a cable television (CATV) network, a processor receives a signal to be amplified by an amplifier at a location remote from the processor. A bias point of the amplifier may be variably modulated based on peaks of an input signal to reduce amplifier dissipation.

Abstract: A radio frequency over glass (RFoG) system may be modified to extend a downstream band. A transimpedance amplifier with a downstream path may be used in the RFoG system in combination with an upstream path having greater than 200 MHz radio frequency (RF) bandwidth to provide the greater than 1.2 GHz downstream bandwidth overlapping with the greater than 200 MHz upstream bandwidth. The RFoG system may include a gateway facilitating an optical network unit and modem connection, the gateway having an express upstream port and an express downstream radio frequency (RF) port. The gateway may be configured for processing legacy RFoG signals in an upstream and a downstream direction and for at least one of generating or processing, via the express ports on the modem, RFoG signals in an extended spectrum beyond 42 MHz in the upstream direction and beyond 1000 MHz in the downstream direction.

Abstract: A pressure sensor includes a single mode fiber, a Bragg grating, and a polarization controller to generate additional polarization states from an input polarization state of light injected into the fiber. The sensor utilizes logic to detect a uni-axial pressure applied to the fiber that shifts a reflection wavelength of a first Bragg grating polarization state relative to a Bragg reflection wavelength of a second polarization state orthogonal to the first polarization state.

Abstract: A pressure sensor includes a single-mode optical fiber and a fiber Bragg grating coupled to the single model fiber. The sensor detects a wavelength shift of a reflection spectrum of the Bragg grating for input light signals to the single mode fiber at different polarization states. A pressure measurement is obtained by determining at least a pair of mutually orthogonal polarization states for the input light at which the wavelength shift of a reflection spectrum of the Bragg grating is a maximum.

Abstract: Implementing a laser into a system that uses a remote powered combiner or an aggregating combiner (AC) with one or more in-range contributing combiners may provide power to the downstream contributing combiners (CC). The power may be provided on the same fiber that downstream signals and the upstream signals traverse.

Abstract: Implementing a laser into a system that uses a remote powered combiner or an aggregating combiner (AC) with one or more in-range contributing combiners may provide power to the downstream contributing combiners (CC). The power may be provided on the same fiber that downstream signals and the upstream signals traverse.

Abstract: Systems and methods for relaying upstream signals received from a plurality of subscribers to a remote head end. Preferably, the systems and methods use a switch that selectively opens when upstream RF signals are not present and closes when upstream RF signals are present, in a manner that reduces noise.

Abstract: The disclosed system and method provide for a CATV power amplifier in which power dissipation may be reduced by dynamically adjusting the amplifier bias such that the bias is high only when high peak output signals need to be produced. By combining a bias control signal and an RF data signal into a single signal produced by a single DA converter, the disclosed examples require fewer DA converters and a need to synchronize DA converters to produce each of the signals individually is eliminated. A low frequency signal may be added to the RF band to find an optimum compromise between positive and negative peak excursions produced by the amplifier such that an overall reduction in bias may be achieved.