Abstract: Systems and methods for preventing laser clipping in a CATV network.

Abstract: Systems and methods for detecting laser transmission bursts in a CATV network.

Abstract: A multimode combiner or coupler (MMC) may combine the inputs into a larger core multimode fiber. The multimode combiner may be combined with a re-transmitting laser for detecting and re-transmitting signals. Thus, the multi-mode combiner may detect and combine input signals, and then retransmit the detected, combined signal. The detection can be implemented with multiple single mode fibers to small single mode detectors or a multi-mode coupler with a larger multi-mode detectors. In embodiments of the MMC, a bi-directional optical splitter/combiner includes a transmitter for re-transmitting an RF signal received at a receiver, a first wave division multiplexer (WDM) combiner combining the output of the first transmitter in an upstream direction to a downstream signal in a downstream direction, and a second WDM combiner combining split downstream signals in the downstream direction with upstream signals received via at least two optical fiber inputs.

Abstract: Powering an active/splitter and providing information to ONUs to cause adjustments to ONU operating wavelengths. An ONU may identify the port of a splitter to which the ONU is connected in order to make wavelength adjustments. Various techniques enable the ONU to identify from which port the ONU is receiving signals, such as a splitter that splits signals to ONUs in a cable network and signals to one or more ONUs the port to which it is connected. The splitter may lack electrical power and may perform the signal function by harvesting optical power from optical power provided to the splitter. In this manner, an active splitter may behave passively with respect to powering components in the absence of electrical power.

Abstract: An active optical combiner for a CATV network.

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: Systems and methods for optical modulation index calibration in a CATV network.

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: A smart receiver and smart transmitter for CATV networks where distortion is minimized using a spectrum analyzer.

Abstract: An optical amplifier with network optimization techniques maximizes performance of a conventional optical amplifier with minimum user intervention. A circulator enables as much light as possible just below a stimulated Brillouin scattering threshold to be launched in to an optical fiber. An amount of reflected power directed by a circulator to a photo diode has a direct correlation to the quality of the received signal in a communications system.

Abstract: A multi-wavelength CATV transmission system includes transmitters adapted to emit carrier wavelengths on a 12.5 GHz+/?20% ITU grid with a minimum spacing between carriers and/or carriers and their beat product groups of 37.5 GHz+/?20%.

Abstract: Methods and systems for using a signal to generate a pilot tone to modulate the bias point of an amplifier that amplifies the signal.

Abstract: The methods, systems, and apparatuses described in this disclosure enable the use of pluggable optics such that two outgoing connections or two incoming connections can support the use of dual transmitter optics and/or dual receiver optics. The forward and/or reverse capacity of an optical network can be doubled using two transmitters and/or receivers operating in parallel. In embodiments, forward and/or reverse capacity of an optical network can be doubled using a double capacity transmitter or receiver that is operable to combine two or more electrical signals into a single optical signal. A pluggable can support two transmitting or two receiving optical links, and can also support a double capacity transmitting or receiving optical link.

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: Methods and apparatuses for controlling a bias point voltage for an external optical modulator are provided. A control loop is used to adjust a bias signal applied to an external modulator by determining unwanted signals at a predetermined frequency received by an optical receiver of the control loop and accounting for these unwanted signals when determining the bias point voltage.

Abstract: Methods and apparatuses are provided to determine whether SBS is present in a fiber of a communication system. An SBS detector comprising a circulator and a detector is used to determine whether SBS is occurring in a fiber. An input optical signal can be received at a first port of the circulator and output at a second port of the circulator where the fiber is connected. The circulator can receive a reflected optical signal from the fiber at the second port of the circulator and output the reflected optical signal at the third port. A detector connected to third port of the circulator receives the reflected optical signal and converts the reflected optical signal to a D.C. voltage.

Abstract: Methods and apparatuses for controlling a bias point voltage for an external optical modulator are provided. A control loop is used to adjust a bias signal applied to an external modulator by determining unwanted signals at a predetermined frequency received by an optical receiver of the control loop and accounting for these unwanted signals when determining the bias point voltage.

Abstract: A cable television (CATV) distribution system, and a method of forming and using the CATV distribution system. In a first embodiment, a narrowcast optical signal is generated by an uncooled laser and converted by a receiver into a narrowcast electrical signal. In a second embodiment, a narrowcast optical signal generated by an uncooled laser is combined with a broadcast optical signal by an optical coupler at a hub of the CATV distribution system to generate a composite optical signal, which at a CATV node is: split into the broadcast and narrowcast optical components, respectively converted into broadcast and narrowcast electrical components, and combined into a composite electrical signal. In a third embodiment, a narrowcast optical signal is generated by an uncooled laser and then combined with the broadcast optical signal by a single receiver.

Abstract: A method and apparatus for a wavelength division multiplexing (WDM) optical transmission system wherein the optical transmission system has an optical signal transmitter which functions as a passive hub, in which only optical signal processing is performed, while associated electronic signal processing is performed outside the passive hub. The passive hub includes upconverter devices that place the optical signal bands at frequencies that allow separation of the bands at a detector. The detectors are thus loaded with more than one wavelength at a time. The optical transmission signals are optically combined and/or amplified onto a single fiber that is fed to a headend device, where the wavelengths of the optical transmission signals are demultiplexed and fed to the receivers.

Abstract: A laser transmitter bias circuit for a laser diode transmitter, for use in a optical transmission system, e.g. in commercial CATV systems. The laser transmitter bias circuit reduces power consumption and heat dissipation by eliminating the conventional need for a distinct constant DC current supply for biasing the laser diode. Radio frequency (RF) circuitry, e.g., a radio frequency amplifier (e.g., a Hybrid Amplifier), connected in series to the laser diode supplies both a DC bias-current (IB) and an RF drive-current (IP) through the laser diode. The DC bias current through the laser diode in turn powers (and/or biases) the radio frequency amplifier and, optionally, other radio frequency circuitry. An optional diode-bypass current (IBP) path may be connected in parallel with the laser diode, and in series with the radio frequency amplifier to control bias current.