Abstract: An apparatus, e.g. an optical receiver, includes an optical front end and a processor. The optical front end is configured to coherently receive an input optical signal and convert the input optical signal to a digital-electrical data stream. The processor is configured to recover a data stream from the digital-electrical data stream. The processor is further configured to compare a correlation pattern of the recovered data stream with a pre-determined correlation pattern. The processor is further configured to determine, from the comparison, coefficients of a filter configured to recover data encoded on the input digital-electrical data stream.

Abstract: An apparatus, e.g. an optical receiver, includes an optical front end and a processor. The optical front end is configured to coherently receive an input optical signal and convert the input optical signal to a digital-electrical data stream. The processor is configured to recover a data stream from the digital-electrical data stream. The processor is further configured to compare a correlation pattern of the recovered data stream with a pre-determined correlation pattern. The processor is further configured to determine, from the comparison, coefficients of a filter configured to recover data encoded on the input digital-electrical data stream.

Abstract: Embodiments for optical communication are provided in which tunable receiver selects and demodulates a first channel of a WDM signal. An example receiver includes a tunable local oscillator for generating a local oscillator signal approximately centered at a first channel wavelength. An optical hybrid of the receiver receives at a first input a wavelength-division-multiplexed (WDM) signal with a M-ary modulation scheme, wherein M is an integer greater than 2, and at a second input the local oscillator signal. A plurality of detectors detect in-phase and quadrature components of the first channel wavelength output of the optical hybrid, which are digitizing by a plurality of analog-to-digital converters. A digital signal processor processes the digitized in-phase and quadrature components in order to recover data carried by the first channel of the WDM signal.

Abstract: An optical router is disclosed having at least one frequency router. The frequency router includes a plurality of input ports and a plurality of output ports. At least one input port simultaneously receives at least two optical signals to be frequency routed, while at least one output port simultaneously presents at least two frequency routed optical signals. Each optical signal to be frequency routed is colored in response to destination information.

Abstract: Certain embodiments of the present invention provide a monitoring system configured to monitor output wavelengths, power, and channel switching of tunable lasers employed in an optical transmitter and provide feedback to those lasers, e.g., to lock on the wavelengths corresponding to optical channels in the transmitter. The monitoring system has a monitoring switch fabric, such as an optical waveguide grating (AWG), and one or more photodetector arrays coupled to the transmitter. Optical channels in the monitoring AWG may be offset relative to the optical channels in the transmitter and shaped to allow more sensitive monitoring of, e.g., wavelength drifting of the tunable lasers. The monitoring system may track the lasers in a non-disruptive continuous manner while data is transmitted through the transmitter.

Abstract: A switch employs two or more parallel optical switch fabrics, e.g., arrayed waveguide gratings (AWG), combined with a set of transmitter cards. Each transmitter card has a tunable laser and two or more modulators, each configured to modulate a different copy of the output of the laser with a different set of data. Outputs of the modulators in each transmitter card are coupled to a set of corresponding input ports in the AWGs. A set of receiver cards, each receiver card having the number of receivers matching that of modulators in the transmitter cards, is coupled to output ports of the AWGs, such that each receiver card receives signals from a set of corresponding output ports in the AWGs. Each transmitter card can be configured to send data to any receiver card by setting the wavelength of its laser to the value corresponding to the set of output ports in the AWGs coupled to that receiver card. A parallelized optical switch may be optimized based on a desired set of criteria, e.g.

Abstract: Certain embodiments of the present invention provide a monitoring system configured to monitor output wavelengths, power, and channel switching of tunable lasers employed in an optical transmitter and provide feedback to those lasers, e.g., to lock on the wavelengths corresponding to optical channels in the transmitter. The monitoring system has a monitoring switch fabric, such as an optical waveguide grating (AWG), and one or more photodetector arrays coupled to the transmitter. Optical channels in the monitoring AWG may be offset relative to the optical channels in the transmitter and shaped to allow more sensitive monitoring of, e.g., wavelength drifting of the tunable lasers. The monitoring system may track the lasers in a non-disruptive continuous manner while data is transmitted through the transmitter.

Abstract: An optical switch configured to reduce packet-to-packet optical power variation corresponding to different switch channels. The optical switch includes a plurality of optical amplifiers coupled to the input or output ports of an optical switch fabric (OSF), e.g., an arrayed waveguide grating. Each amplifier may be a semiconductor optical amplifier configured to operate in the saturated regime. In addition, the maximum output power of each amplifier may be set to a different value related to the insertion loss in the OSF. As a result, at each receiver corresponding to an output port of the OSF, the optical power corresponding to data packets arriving from different input ports may be substantially equalized. Such equalization may reduce the number of bit errors in the switch.

Abstract: A switch employs two or more parallel optical switch fabrics, e.g., arrayed waveguide gratings (AWG), combined with a set of transmitter cards. Each transmitter card has a tunable laser and two or more modulators, each configured to modulate a different copy of the output of the laser with a different set of data. Outputs of the modulators in each transmitter card are coupled to a set of corresponding input ports in the AWGs. A set of receiver cards, each receiver card having the number of receivers matching that of modulators in the transmitter cards, is coupled to output ports of the AWGs, such that each receiver card receives signals from a set of corresponding output ports in the AWGs. Each transmitter card can be configured to send data to any receiver card by setting the wavelength of its laser to the value corresponding to the set of output ports in the AWGs coupled to that receiver card. A parallelized optical switch may be optimized based on a desired set of criteria, e.g.

Abstract: Apparatus for measuring the dispersion and dispersion parameter of an optical fiber as a function of distance (the dispersion map) by the optical-time-domain reflection technique uses a multi-frequency laser with an extra cavity semiconductor optical amplifier switch to generate the short pulses of two wavelengths to displace the four-wave mixing oscillations away from the origin of the complex plane. Additionally laser power is supplied at both ends of the fiber under test to provide pump power to Raman amplify the backscattered signal being measured. Finally a novel Fast Fourier Transform based algorithm is used to calculate the dispersion map fast and accurately.