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: Particular embodiments provide a method for delivering data in the upstream direction without the need for upstream radio frequency (RF) modulation. For example, in some embodiments, an optical network may reach to a gateway associated with a user device. The gateway may receive digital baseband data from the user device in the upstream direction. The gateway can then send the digital baseband data through the optical network without modulating the digital baseband signal via radio frequency. At the headend, because no modulation is performed in the upstream direction, there is no need for de-modulation in the headend. In one embodiment, a scheduler-based approach is used to avoid instances of optical beat interference in the upstream direction as only one upstream device that may interfere with other devices may be able to send data at one time.

Abstract: An OBI manager provides the reduction/elimination of optical beat interference (OBI). As will be described in more detail below, the OBI manager identifies OBI partners through an identification process performed via an RFoG network. An OBI partner may be two optical networking units (ONUs) that may interfere with one another when transmitting in the same time slot. Once the OBI partners are identified, the OBI manager may perform a mitigation process to mitigate possible OBI. For example, the OBI manager may organize the OBI partners to reduce OBI, such as by guaranteeing no OBI partners transmit at the same time.

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: 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: An OBI manager provides the reduction/elimination of optical beat interference (OBI). As will be described in more detail below, the OBI manager identifies OBI partners through an identification process performed via an RFoG network. An OBI partner may be two optical networking units (ONUs) that may interfere with one another when transmitting in the same time slot. Once the OBI partners are identified, the OBI manager may perform a mitigation process to mitigate possible OBI. For example, the OBI manager may organize the OBI partners to reduce OBI, such as by guaranteeing no OBI partners transmit at the same time.

Abstract: An OBI manager provides the reduction/elimination of optical beat interference (OBI). As will be described in more detail below, the OBI manager identifies OBI partners through an identification process performed via an RFoG network. An OBI partner may be two optical networking units (ONUs) that may interfere with one another when transmitting in the same time slot. Once the OBI partners are identified, the OBI manager may perform a mitigation process to mitigate possible OBI. For example, the OBI manager may organize the OBI partners to reduce OBI, such as by guaranteeing no OBI partners transmit at the same time.

Abstract: Particular embodiments provide a method for delivering data in the upstream direction without the need for upstream radio frequency (RF) modulation. For example, in some embodiments, an optical network may reach to a gateway associated with a user device. The gateway may receive digital baseband data from the user device in the upstream direction. The gateway can then send the digital baseband data through the optical network without modulating the digital baseband signal via radio frequency. At the headend, because no modulation is performed in the upstream direction, there is no need for de-modulation in the headend. In one embodiment, a scheduler-based approach is used to avoid instances of optical beat interference in the upstream direction as only one upstream device that may interfere with other devices may be able to send data at one time.

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: An OBI manager provides the reduction/elimination of optical beat interference (OBI). As will be described in more detail below, the OBI manager identifies OBI partners through an identification process performed via an RFoG network. An OBI partner may be two optical networking units (ONUs) that may interfere with one another when transmitting in the same time slot. Once the OBI partners are identified, the OBI manager may perform a mitigation process to mitigate possible OBI. For example, the OBI manager may organize the OBI partners to reduce OBI, such as by guaranteeing no OBI partners transmit at the same time.

Abstract: A headend communications device communicates via a network to downstream network elements, such as cable modems coupled behind optical network units, and allocates and grants timeslots for upstream transmissions from the network elements. The headend communications device has a scheduler for managing and controlling timeslot allocations in a manner avoiding interference such as optical beat interference or FM carrier collisions. The scheduler identifies two or more cable modems or like customer network elements served by the headend communications device that will cause at least a pre-determined intolerable level of interference when allocated overlapping timeslots for upstream transmissions and prevents these two or more cable modems or network elements from being allocated and granted overlapping timeslots.

Abstract: A method and apparatus is provided for reducing clipping arising in an optical transmitter. The method begins by generating a frequency multiplexed sub-carrier signal onto which information is modulated at a plurality of different sub-carrier frequencies. The method continues by decorrelating in phase at least some pulses that are formed when two or more of the different sub-carrier frequencies are in phase with one another. An optical output produced by a laser is modulated in accordance with the frequency multiplexed sub-carrier signal after at least some of the pulses have been decorrelated in phase.

Abstract: Integrated balun and coupler is described. In one example, a radio frequency (RF) device includes a balun and coupler. The balun includes a first winding and a second winding arranged on a magnetic core. Respective inputs of the first winding and the second winding are configured to receive a balanced RF input and respective outputs of the first winding and the second winding are configured to provide a first unbalanced RF output. The coupler includes a third winding arranged on the magnetic core. The third winding is configured to provide a second unbalanced RF output, where the second unbalanced RF output is a fraction of the first unbalanced RF output.

Abstract: A method and apparatus for transferring information of an optical information-bearing signal from a first wavelength to a second wavelength. The method is implemented in an all-optical wavelength converter circuit which includes a laser diode in communication with a polarization controller. An information-bearing signal having a first wavelength is input to the circuit. A polarization controller adjusts the polarization of the information-bearing signal. The laser diode receives the polarization-adjusted information-bearing signal and generates a converted information-bearing signal by transferring the information of the polarization-adjusted information-bearing signal from the first wavelength to the second wavelength. The polarization controller receives the converted information-bearing signal from the laser diode, and polarizes the converted information-bearing signal.

Abstract: High quality epitaxial layers of compound semiconductor materials can be grown overlying large silicon wafers by first growing an accommodating buffer layer on a silicon wafer. An accommodating buffer layer comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline compound semiconductor layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. A composite integrated circuit having a tunable laser is provided. The laser may be mode-locked. Injection-locking may be used to pass optical properties to a slave laser.

Abstract: Composite optical modulation semiconductor structures and methods are provided that are useful for optical communication systems, for example, for modulating user signals in CDMA systems. DBR lasers, waveguides, Bragg gratings, and modulators/encoders are shown that are fabricated within compound semiconductor layers or accommodating layers of a composite semiconductor structure. The composite semiconductor structure is supported by a non-compound semiconductor substrate, that increases manufacturing yields of composite semiconductor structures. Modulating methods shown include electro-optic modulation, piezo-electric modulation, and current injection modulation.