Abstract: A photonics system includes a transmit photonics module and a receive photonics module. The photonics system also includes a transmit waveguide coupled to the transmit photonics module, a first optical switch integrated with the transmit waveguide, and a diagnostics waveguide optically coupled to the first optical switch. The photonics system further includes a receive waveguide coupled to the receive photonics module and a second optical switch integrated with the receive waveguide and optically coupled to the diagnostics waveguide.

Abstract: A photonics system includes a transmit photonics module and a receive photonics module. The photonics system also includes a transmit waveguide coupled to the transmit photonics module, a first optical switch integrated with the transmit waveguide, and a diagnostics waveguide optically coupled to the first optical switch. The photonics system further includes a receive waveguide coupled to the receive photonics module and a second optical switch integrated with the receive waveguide and optically coupled to the diagnostics waveguide.

Abstract: A photonics system includes a transmit photonics module and a receive photonics module. The photonics system also includes a transmit waveguide coupled to the transmit photonics module, a first optical switch integrated with the transmit waveguide, and a diagnostics waveguide optically coupled to the first optical switch. The photonics system further includes a receive waveguide coupled to the receive photonics module and a second optical switch integrated with the receive waveguide and optically coupled to the diagnostics waveguide.

Abstract: A photonics system includes a transmit photonics module and a receive photonics module. The photonics system also includes a transmit waveguide coupled to the transmit photonics module, a first optical switch integrated with the transmit waveguide, and a diagnostics waveguide optically coupled to the first optical switch. The photonics system further includes a receive waveguide coupled to the receive photonics module and a second optical switch integrated with the receive waveguide and optically coupled to the diagnostics waveguide.

Abstract: A method of operating a BPSK modulator includes receiving an RF signal at the BPSK modulator and splitting the RF signal into a first portion and a second portion that is inverted with respect to the first portion. The method also includes receiving the first portion at a first arm of the BPSK modulator, receiving the second portion at a second arm of the BPSK modulator, applying a first tone to the first arm of the BPSK modulator, and applying a second tone to the second arm of the BPSK modulator. The method further includes measuring a power associated with an output of the BPSK modulator and adjusting a phase applied to at least one of the first arm of the BPSK modulator or the second arm of the BPSK modulator in response to the measured power.

Abstract: An optical network unit includes a transmit/receive port and a silicon waveguide optically coupled to the transmit/receive port. The optical network unit also includes a tunable filter coupled to the silicon waveguide and providing a first output for a first frequency band and a second output for a second frequency band. The optical network unit further includes a polarization diverse receiver coupled to the tunable filter and a laser coupled to the tunable filter.

Abstract: An optical modulator includes an input port, a first waveguide region comprising silicon and optically coupled to the input port, and a waveguide splitter optically coupled to the first waveguide region and having a first output and a second output. The optical modulator also includes a first phase adjustment section optically coupled to the first output and comprising a first III-V diode and a second phase adjustment section optically coupled to the second output and comprising a second III-V diode. The optical modulator further includes a waveguide coupler optically coupled to the first phase adjustment section and the second phase adjustment section, a second waveguide region comprising silicon and optically coupled to the waveguide coupler, and an output port optically coupled to the second waveguide region.

Abstract: An optical network unit includes a transmit/receive port and a silicon waveguide optically coupled to the transmit/receive port. The optical network unit also includes a tunable filter coupled to the silicon waveguide and providing a first output for a first frequency band and a second output for a second frequency band. The optical network unit further includes a polarization diverse receiver coupled to the tunable filter and a laser coupled to the tunable filter.

Abstract: A multi-channel transceiver using a floating frequency grid for multi-channel, optical communication is presented. Transmitter frequencies are permitted to drift, and a receiver is tuned to compensate for drifts in the transmitter frequencies.

Abstract: A photonics system includes a transmit photonics module and a receive photonics module. The photonics system also includes a transmit waveguide coupled to the transmit photonics module, a first optical switch integrated with the transmit waveguide, and a diagnostics waveguide optically coupled to the first optical switch. The photonics system further includes a receive waveguide coupled to the receive photonics module and a second optical switch integrated with the receive waveguide and optically coupled to the diagnostics waveguide.

Abstract: An optical network unit includes a transmit/receive port and a silicon waveguide optically coupled to the transmit/receive port. The optical network unit also includes a tunable filter coupled to the silicon waveguide and providing a first output for a first frequency band and a second output for a second frequency band. The optical network unit further includes a polarization diverse receiver coupled to the tunable filter and a laser coupled to the tunable filter.

Abstract: A transceiver includes an optical waveguide and a first filter optically coupled to the optical waveguide and operable to filter a first optical signal in a first wavelength band propagating downstream. A center wavelength of the first wavelength band is tunable. The transceiver also includes a first receiver optically coupled to the first filter and a second filter optically coupled to the optical waveguide and operable to filter a second optical signal in a second wavelength band propagating downstream. The second wavelength band is different from the first wavelength band. The transceiver further includes a second receiver optically coupled to the second filter to receive the second optical signal and a laser optically coupled to the optical waveguide and operable to output radiation in a third wavelength band propagating upstream. The third wavelength band is different from both the first wavelength band and the second wavelength band.

Abstract: A photonics system includes a transmit photonics module and a receive photonics module. The photonics system also includes a transmit waveguide coupled to the transmit photonics module, a first optical switch integrated with the transmit waveguide, and a diagnostics waveguide optically coupled to the first optical switch. The photonics system further includes a receive waveguide coupled to the receive photonics module and a second optical switch integrated with the receive waveguide and optically coupled to the diagnostics waveguide.

Abstract: A multi-channel transceiver using a floating frequency grid for multi-channel, optical communication is presented. Transmitter frequencies are permitted to drift, and a receiver is tuned to compensate for drifts in the transmitter frequencies.

Abstract: An optical network unit includes a transmit/receive port and a silicon waveguide optically coupled to the transmit/receive port. The optical network unit also includes a tunable filter coupled to the silicon waveguide and providing a first output for a first frequency band and a second output for a second frequency band. The optical network unit further includes a polarization diverse receiver coupled to the tunable filter and a laser coupled to the tunable filter.

Abstract: A photonics system includes a transmit photonics module and a receive photonics module. The photonics system also includes a transmit waveguide coupled to the transmit photonics module, a first optical switch integrated with the transmit waveguide, and a diagnostics waveguide optically coupled to the first optical switch. The photonics system further includes a receive waveguide coupled to the receive photonics module and a second optical switch integrated with the receive waveguide and optically coupled to the diagnostics waveguide.

Abstract: An approach for tracking denial-of-service (DoS) flood attacks using an overlay IP (Internet Protocol) network is disclosed. One or more tracking routers form an overlay tracking network over the network of an Internet Service Provider (ISP). The ISP network includes numerous transit routers and edge routers. The tracking routers communicate directly with all the edge routers using IP tunnels. The edge routers within the ISP network perform security diagnostic functions, in part, to identify a DoS flood attack that has been launched by one or more attackers. To track down an attacker, an egress edge router identifies the DoS flood attack datagrams, rerouting these datagrams to the overlay tracking network. The tracking routers perform hop-by-hop input debugging to identify the ingress edge router associated with the source of the DoS flood attack.

Abstract: A statistical multiplexer for coding and multiplexing multiple channels of digital television data, or multiple panels of HDTV digital television data. A bit rate need parameter is determined for each encoder in a stat mux group, and an encoding bit rate is allocated to each channel based on its need parameter. A transmission bit rate is allocated to each channel as a time-lagged version of its need parameter to minimize a rate mismatch between the output and the input of a decoder buffer. A packet processor checks for impending decoder buffer overflow or underflow events to set minimum and maximum limits on the transmission bit rate. Moreover, these limits are set based on whether a new transmission bit rate can be implemented before the decoding time stamp (DTS) of the current or next frame.

Abstract: An approach for tracking denial-of-service (DoS) flood attacks using an overlay IP (Internet Protocol) network is disclosed. One or more tracking routers form an overlay tracking network over the network of an Internet Service Provider (ISP). The ISP network includes numerous transit routers and edge routers. The tracking routers communicate directly with all the edge routers using IP tunnels. The edge routers within the ISP network perform security diagnostic functions, in part, to identify a DoS flood attack that has been launched by one or more attackers. To track down an attacker, an egress edge router identifies the DoS flood attack datagrams, rerouting these datagrams to the overlay tracking network. The tracking routers perform hop-by-hop input debugging to identify the ingress edge router associated with the source of the DoS flood attack.

Abstract: Still picture images are encoded and transmitted at reduced rates using the MPEG-2 standard. Video frames are captured for processing at a still picture capture rate that is lower than the video input frame rate. The captured frames are compressed as Intra frames at the input frame rate. Selected ones of the compressed frames are inserted in the MPEG-2 transport stream for communication to a decoder at a still picture repetition rate which is no less, in frames per second, than the capture rate.