Abstract: The present disclosure relates to systems and methods for fast digital signal processor (DSP) optical receiver recovery, namely for optical modems configured on a client side. This approach can be used in optical protection switching (OPS) applications to allow switching between two client links fast, i.e., within 50 ms. A receiver (Rx) digital signal processor (DSP) in an optical receiver includes circuitry configured to detect traffic is interrupted on a current link, enter a holdoff period, and one of i) receive good traffic during the holdoff period and ii) have the holdoff period expire that causes a notification to a host device and retrain to acquire an optical signal.

Abstract: A circuit includes a buffer configured to receive a first Flexible Ethernet (FlexE) frame having 66b blocks including 66b overhead blocks and 66b data blocks, wherein the buffer is configured to accumulate the 66b overhead blocks and the 66b data blocks; a mapping circuit configured to map four x 66b overhead blocks from the buffer into a 257b overhead block and to map a sequence of four x 66b data blocks from the buffer into a 257b data block; and a transmit circuit configured to transmit a second FlexE frame having 257b blocks from the mapping circuit. The mapping circuit can be configured to accumulate four 66b blocks of a same kind from the buffer for mapping into a 257b block, where the same kind is one of overhead and a particular calendar slot n where n=0-19.

Abstract: A circuit includes a buffer configured to receive a first Flexible Ethernet (FlexE) frame having 66b blocks including 66b overhead blocks and 66b data blocks, wherein the buffer is configured to accumulate the 66b overhead blocks and the 66b data blocks; a mapping circuit configured to map four x 66b overhead blocks from the buffer into a 257b overhead block and to map a sequence of four x 66b data blocks from the buffer into a 257b data block; and a transmit circuit configured to transmit a second FlexE frame having 257b blocks from the mapping circuit. The mapping circuit can be configured to accumulate four 66b blocks of a same kind from the buffer for mapping into a 257b block, where the same kind is one of overhead and a particular calendar slot n where n=0-19.

Abstract: Flexible Ethernet (FlexE) Forward Error Correction (FEC) systems and methods include mapping a first set of calendar slots including Ethernet payload clients to a FlexE Time Division Multiplexing (TDM) structure including a plurality of calendar slots; and mapping a second set of calendar slots including FEC data to the FlexE TDM structure, wherein the first set of calendar slots and the second set of calendar slots fill the FlexE TDM structure. In an exemplary embodiment, an overall Physical (PHY) rate of the FlexE TDM structure is kept constant with a reduction in bandwidth for the Ethernet payload clients based on the second set. In another exemplary embodiment, the overall Physical (PHY) rate of the FlexE TDM structure is increased based on the second set of calendar slots, to support a set rate for the Ethernet payload clients with a reduced number of calendar slots.

Abstract: Flexible Ethernet (FlexE) Forward Error Correction (FEC) systems and methods include mapping a first set of calendar slots including Ethernet payload clients to a FlexE Time Division Multiplexing (TDM) structure including a plurality of calendar slots; and mapping a second set of calendar slots including FEC data to the FlexE TDM structure, wherein the first set of calendar slots and the second set of calendar slots fill the FlexE TDM structure. In an exemplary embodiment, an overall Physical (PHY) rate of the FlexE TDM structure is kept constant with a reduction in bandwidth for the Ethernet payload clients based on the second set. In another exemplary embodiment, the overall Physical (PHY) rate of the FlexE TDM structure is increased based on the second set of calendar slots, to support a set rate for the Ethernet payload clients with a reduced number of calendar slots.

Abstract: An optical data storage system directs a reference beam and a data beam to a storage material having an inhomogeneous linewidth. The data beam is modulated to contain data to be stored in the storage material. The reference beam and the data beam illuminate storage cells of the storage material, causing data to be stored. The reference beam and the data beam spatially scan the cells and are frequency swept during their respective spatial scans. Data is retrieved from the cells by illuminating the storage material with the reference beam to produce a reconstructed data beam. In an embodiment, the reference beam and the data beam overlap and illuminate the storage cells simultaneously. The reconstructed data beam is detected as a heterodyne signal produced by mixing the reconstructed data beam and the reference beam in a detector.

Abstract: Optical communication systems include a central station that encodes data transmitted to multiplexing (mux) stations or user stations. The central station also decodes data received from the mux stations or user stations. Encoding and decoding are performed using codes, such as composite codes, that designate sources and destinations for data. The mux stations, user stations, and the central station have address encoders and decoders that use, for example, fiber Bragg gratings to encode or decode optical signals according to a code such as a composite code derived by combining codes from one or more sets of codes. A passive optical network comprises one or more levels of mux stations that use such address decoders and encoders to receive, decode, and encode data for transmission toward a central station or a user station.

Abstract: An optical data storage system directs a reference beam and a data beam to a storage material having an inhomogeneous linewidth. The data beam is modulated to contain data to be stored in the storage material. The reference beam and the data beam illuminate storage cells of the storage material, causing data to be stored. The reference beam and the data beam spatially scan the cells and are frequency swept during their respective spatial scans. Data is retrieved from the cells by illuminating the storage material with the reference beam to produce a reconstructed data beam. In an embodiment, the reference beam and the data beam overlap and illuminate the storage cells simultaneously. The reconstructed data beam is detected as a heterodyne signal produced by mixing the reconstructed data beam and the reference beam in a detector.

Abstract: Communication systems and methods are disclosed that route, detect, and decode encoded optical signals at network nodes based on channel codes assigned to the network nodes. In an example communication system, a network hub includes a channel selector that encodes an optical signal with a channel code assigned to one or more network nodes. The channel selector is configured to encode based on a channel selection signal provided to the channel selector and can include one or more fiber Bragg coders. Code-switched communication systems can include one or more nodes configured in ring, tree, or bus architectures.

Abstract: A method for determining optical power in a WDM optical signal that includes extracting a representative portion of the optical signal with wavelengths within some band ? wherein ? is a subset of ?, the set of all channel wavelengths present in the optical signal and measuring the intensity of the extracted optical signal to determine the optical power per channel for any of the channels whose wavelengths are within the band ?.

Abstract: A method for determining optical power in a WDM optical signal that includes extracting a representative portion of the optical signal with wavelengths within some band &dgr; wherein &dgr; is a subset of &Dgr;, the set of all channel wavelengths present in the optical signal and measuring the intensity of the extracted optical signal to determine the optical power per channel for any of the channels whose wavelengths are within the band &dgr;.

Abstract: Code-multiplexed communication systems, apparatus, and methods include coders that encode and decode data streams with synchronous, substantially orthogonal codes. Code-multiplexed communications systems encode data signals with such codes to control levels of decoding artifacts such as cross-talk at times or time intervals in which data is recovered. Some systems are based on synchronous, orthogonal codes that are obtained from complex orthogonal vectors. In an example, a three-level temporal-phase code that includes nine code chips and encodes and decodes data signals is a seven-channel communication system.

Abstract: Charge-transfer materials are demonstrated to be useful for generating femtosecond holographic gratings. Using semiconducting polymers sensitized with varying concentrations of C60, absorption holographic gratings with diffraction efficiencies of 1.6% were recorded with individual ultrafast laser pulses; the diffraction efficiency and time decay of the gratings were measured using nondegenerate four-wave mixing. High quantum efficiency for electron transfer reduces the effects of early recombination which otherwise limits the density of excitations in pure polymers, and the metastability of the charge transfer enables tuning of the decay dynamics by controlling the concentration of acceptors in the mixture.

Abstract: An optical data storage system directs a reference beam and a data beam to a storage material having an inhomogeneous linewidth. The data beam is modulated to contain data to be stored in the storage material. The reference beam and the data beam illuminate storage cells of the storage material, causing data to be stored. The reference beam and the data beam spatially scan the cells and are frequency swept during their respective spatial scans. Data is retrieved from the cells by illuminating the storage material with the reference beam to produce a reconstructed data beam. In an embodiment, the reference beam and the data beam overlap and illuminate the storage cells simultaneously. The reconstructed data beam is detected as a heterodyne signal produced by mixing the reconstructed data beam and the reference beam in a detector.

Abstract: An optical data storage system directs a reference beam and a data beam to a storage material having an inhomogeneous linewidth. The data beam is modulated to contain data to be stored in the storage material. The reference beam and the data beam illuminate storage cells of the storage material, causing data to be stored. The reference beam and the data beam spatially scan the cells and are frequency swept during their respective spatial scans. Data is retrieved from the cells by illuminating the storage material with the reference beam to produce a reconstructed data beam. In an embodiment, the reference beam and the data beam overlap and illuminate the storage cells simultaneously. The reconstructed data beam is detected as a heterodyne signal produced by mixing the reconstructed data beam and the reference beam in a detector.

Abstract: In a method and apparatus for tracking dynamic characteristics of an optical amplifier, optical signal probes are used to determine the gain and the corner frequency of the optical amplifier. A first optical probe having a predetermined modulation frequency above an expected corner frequency of the amplifier is used to estimate the gain of the optical amplifier. A second optical probe signal having a second predetermined modulation frequency at or below the expected corner frequency of the amplifier is used to estimate the corner frequency. These parameters can be used to optimize gain control of an optical amplifier.

Abstract: An optical data storage system directs a reference beam and a data beam to a storage material having an inhomogeneous linewidth. The data beam is modulated to contain data to be stored in the storage material. The reference beam and the data beam illuminate storage cells of the storage material, causing data to be stored. The reference beam and the data beam spatially scan the cells and are frequency swept during their respective spatial scans. Data is retrieved from the cells by illuminating the storage material with the reference beam to produce a reconstructed data beam. In an embodiment, the reference beam and the data beam overlap and illuminate the storage cells simultaneously. The reconstructed data beam is detected as a heterodyne signal produced by mixing the reconstructed data beam and the reference beam in a detector.

Abstract: In a method and apparatus for tracking dynamic characteristics of an optical amplifier, optical signal probes are used to determine the gain and the corner frequency of the optical amplifier. A first optical probe having a predetermined modulation frequency above an expected corner frequency of the amplifier is used to estimate the gain of the optical amplifier. A second optical probe signal having a second predetermined modulation frequency at or below the expected corner frequency of the amplifier is used to estimate the corner frequency. These parameters can be used to optimize gain control of an optical amplifier.

Abstract: Programmable waveguide coders are disclosed that include one or more corrugation segments and one or more spacer segments formed on or in a waveguide defined by a core in an electro-optic substrate. Each of the corrugation segments and the spacer segments are independently controllable with voltages applied to each segment's electrodes. The spacer segments permit application of a phase modulation to an input while the corrugation segments act as tunable gratings, wherein a center grating wavelength is tunable by applying a voltage to an electrode associated with the corrugation segment. In some embodiments, coders include only corrugation segments or only spacer segments. Such coders can be strain tuned or thermally tuned. The coders can be programmatically tuned to code or decode a time-wavelength code or other code.

Abstract: Charge-transfer materials are demonstrated to be useful for generating femtosecond holographic gratings. Using semiconducting polymers sensitized with varying concentrations of C60, absorption holographic gratings with diffraction efficiencies of 1.6% were recorded with individual ultrafast laser pulses; the diffraction efficiency and time decay of the gratings were measured using nondegenerate four-wave mixing. High quantum efficiency for electron transfer reduces the effects of early recombination which otherwise limits the density of excitations in pure polymers, and the metastability of the charge transfer enables tuning of the decay dynamics by controlling the concentration of acceptors in the mixture.