Abstract: All optical clock recovery includes a transmitter for generating an optical timing signal. The transmitter includes a semiconductor laser for the production of a dynamically synchronizable timing signal, the laser having an external resonator for feedback of the timing signal to the laser, the feedback having a delay time greater than a relaxation oscillation time for the laser, and the laser outputting an optical timing signal having a characteristic dynamic. The transmitter supplies the optical timing signal to a receiver configured to receive the timing signal and to synchronize to the laser on receipt of the timing signal, such that the receiver outputs a recovered timing signal having the characteristic dynamic.

Abstract: A regenerator for restoring the originally encoded optical phase of a differential-phase-shift-keyed signal. In an embodiment, the regenerator simultaneously provides limiting amplification and reduces amplitude noise based on a phase-sensitive optical amplifier that combines a weak signal field of a degraded input data with a strong pump field supplied by a local oscillator in a nonlinear interferometer. The two fields interact through degenerate four-wave mixing, and optical energy is transferred from the pump to the signal and vice versa. The phase sensitive nature of the optical gain leads to amplification of a specific phase component of the signal, determined by the input pump-signal phase difference and the incident signal phase is restored to two distinct states, separated by 180° according to the original encoding. Simultaneously, gain saturation of the pump wave by the signal wave results in limiting amplification of the signal wave for removing signal amplitude noise.

Abstract: Optical bypass node upgrade configurations are disclosed: (1) a configuration where optical taps are pre-positioned in wavelength division multiplex (WDM) line systems terminating at optical-electrical-optical (OEO) core switching nodes to allow for future upgrade of the nodes to degree-two or higher optical bypass; (2) a configuration where the taps are pre-positioned in a degree-two optical bypass node to allow for future upgrade to a degree-N optical bypass node; and (3) a configuration and procedure for upgrading OEO core switching nodes to optical bypass when the taps have not been pre-positioned in the WDM line systems. These configurations do not introduce bit errors for non-upgraded optical paths.

Abstract: A method for adding a new wavelength to an optical communication network is provided. One step of the method includes installing a transmitter component in a transmitter node of the optical communication network. Another step includes installing a receiver component in a receiver node of the optical communication network. For each of a plurality of regenerator nodes in the optical communication network, the method includes the steps of determining whether the quality of optical signals for the new wavelength at the particular regenerator node satisfies a performance threshold, installing an optical regenerator component in the regenerator node for regenerating the optical signals if the quality of the optical signals at the regenerator node satisfies the performance threshold, and installing optical-to-electrical-to-optical regenerator components if the quality of the optical signals at the regenerator node does not satisfy the performance threshold.

Abstract: The discrimination phase margin monitor circuit (10) of the present invention comprises a first discrimination circuit (11 and 12) discriminating an input data signal using a clock signal extracted from the input data signal, a second discrimination circuit (13 and 14) discriminating the input data signal using a clock signal with a frequency different from that of the clock and an operation circuit (15 and 16) calculating the exclusive OR of the output signal of the first discrimination circuit and that of the second discrimination circuit and obtaining a phase margin monitor output signal by averaging the exclusive ORs.

Abstract: An optical pulse position modulation receiver relying on the gain dynamics in a semiconductor optical amplifier (SOA). Optical PPM signal pulses and periodic optical clock pulses at a different frequency and/or polarization than the signal pulses are coupled into an SOA. Due to the high optical power of the clock pulses, the SOA gain will drop to a small value after each clock pulse. The SOA will then amplify each signal pulse that follows the clock pulse, and the gain will depend on the delay between the signal pulse and the preceding optical clock pulse. The optical output of the SOA can then be converted to an electrical signal by a photodetector.

Abstract: A receiver transponder to be used in an optical add and drop multiplexer connected in short haul type networks receives light signals from two opposite directions on input fibers (21, 23). The optical input signals are converted to electrical signals by O/E converters (51, 53). The output terminals of the converters are connected to an electronic switch (61) which handles protection switching in a protected ring type network. The output of the switch can be monitored (65) before, it enters a reshaping circuit (67) in which the signal is reshaped, cleansed from a supervisory channel and given a proper drive level for a following laser (69). The optical signal from the laser can travel a significant distance through a fiber (71) to a client receiver or sustain other forms of attenuation and still have a sufficient signal power for reliable detection. An electrical output signal can be provided (73) by the reshaping circuit.

Abstract: An optical network includes an optical ring having a plurality of subnets. The subnets each include one or more add/drop nodes that are coupled to the optical ring and that passively add and drop traffic to and from the optical ring in one or more wavelengths. The optical network also includes a plurality of gateway nodes that are each coupled to the optical ring at a boundary between neighboring subnets. Each gateway node forwards a first copy of a received optical signal to a multiplexer/demultiplexer unit of the gateway node, which selectively forwards or terminates the traffic in each wavelength of the first copy. The gateway nodes also forward a second copy of the received optical signal to a regeneration element. The gateway nodes selectively forward or terminate the traffic in each wavelength of the first copy at the multiplexer/demultiplexer unit.

Abstract: An optical communication system comprises a first optical interface, an optical processing system, and a second optical interface. The first optical interface receives an optical signal that is phase-modulated and has a first wavelength. The optical processing system converts the first wavelength of the optical signal to a second wavelength that is different from the first wavelength without converting the optical signal into an electrical format. The second optical interface transfers the optical signal that is phase-modulated and has the second wavelength.

Abstract: A digital optical network (DON) is a new approach to low-cost, more compact optical transmitter modules and optical receiver modules for deployment in optical transport networks (OTNs). One important aspect of a digital optical network is the incorporation in these modules of transmitter photonic integrated circuit (TxPIC) chips and receiver photonic integrated circuit (RxPIC) chips in lieu of discrete modulated sources and detector sources with discrete multiplexers or demultiplexers.

Abstract: A multichannel wavelength-division multiplex fiber optic transmission system includes an optical transmitter and an optical receiver connected by an optical line including at least one optical fiber and at least one set of channel regenerators. Successive regenerators regenerate respective groups of channels forming a subset of the set of channels.

Abstract: The present invention is a method of processing an optical signal, including the steps of (a) inputting signal light into a first nonlinear optical medium to broaden the spectrum of the signal light through self phase modulation occurring in the first nonlinear optical medium, thereby obtaining first spectrally broadened light, (b) compensating for chromatic dispersion effected on the first spectrally broadened light obtained in the step (a), and (c) inputting the first spectrally broadened light processed by the step (b) into a second nonlinear optical medium to broaden the spectrum of the first spectrally broadened light through self phase modulation occurring in the second nonlinear optical medium, thereby obtaining second spectrally broadened light.

Abstract: A method and apparatus for controlling a plurality of infrared devices (ICDs) is provided herein. A remote controller is used to generate an optical signal for controlling a plurality of ICDs. The optical signal generated by the remote controller is converted into an electrical signal by an infrared repeater device. An implementation of such a system includes a rotary mechanical switch to direct the electrical signal generated by the infrared repeater device to a light emitting diode (LED) located near one of the plurality of ICDs. The LED converts the electrical signal into an optical signal and re-transmits the optical signal to the one of the plurality of ICDs. The system allows controlling the plurality of ICDs located in a remote location without having the user commute closer to such ICDs.

Abstract: To demultiplex a low-speed optical pulse signal from a high-speed optical pulse signal, an optical clock generator generates an optical clock of a control wavelength ?p at a predetermined frequency out of a pulse signal light of a signal wavelength ?s. On one side of a saturable absorber, an optical band reflection mirror is disposed to reflect a light of the signal wavelength ?s and to transmit a light of the control wavelength ?p. A pulse signal light of the signal wavelength ?s reciprocates in the saturable absorber. An optical pulse of the pulse signal light of the signal wavelength ?s enters the saturable absorber almost simultaneously with different optical pulses of the optical clock on the ways of going and returning. The saturable absorber has a transmission factor relative to the signal wavelength ?s. The transmission factor varies as the saturable absorber absorbs a light of the control wavelength ?p.

Abstract: A protection arrangement for an optical switching system includes protection switching for switch planes in the optical core and for ports in the tributary cards. For a multiple layer switch core protection is also provided between layers. A first layer is for switching optical channels. The protection switches used may be 1×N, 2×N or 3×N MEMS optical switches. The 1×N MEMS provides for protection switching. The 2×N MEMS provides protection switching and testing capability. The 3×N MEMS provides for protection switching, testing and backup of the protection switching. Application of these protection switches is shown in lambda plane switch cores, multiple layer switch cores and combined switch cores.

Abstract: An optical signal processing method is disclosed that enables improvements of a signal to noise ratio of an optical signal and reduction of size and power of an optical signal processing device. The optical signal processing method includes steps of dividing an input optical signal into a first polarization optical component and a second polarization optical component orthogonal to the first polarization optical component; supplying the first polarization optical component to a first gain device whose gain saturates at a first value; supplying the second polarization optical component to a second gain device whose gain saturates at a second value less than the first value; combining output light from the first gain device and output light from the second gain device; and outputting the combined optical signal through a polarization element.

Abstract: A repeating apparatus and method using wireless optical transmission is disclosed. The repeating apparatus includes a donor device for transmitting two identical copies of an optical signal by receiving a RF signal from a base station and electro-optic converting the RF signal to an optical signal, and for transmitting a RF signal by receiving two identical copies of the optical signal and optic-electro converting the optical signal to a RF signal; and a coverage device for transmitting a RF signal to a mobile communication terminal by receiving two identical copies of the optical signal from the donor device and optic-electro converting the two identical copies of the optical signal to the RF signal, and transmitting two optical signals to the donor device by receiving the RF signal from the mobile communication terminal and elector-optic converting the RF signal to the optical signal.

Abstract: A system, method and device for AO2R is presented. The AO2R system presented is redundant, containing multiple pathways for the input and output signals to travel. The system carries out both the regeneration and reshaping functions in the optical domain, and returns a clean output signal at the same bit rate and in the same format as the input signal, on a wavelength of choice. As an all optical device, the apparatus is bit rate and format transparent, and requires no optical-electrical-optical conversion. The system's built in redundancy and symmetry allows less than perfect yields on components to be tolerated, thus increasing the utility of devices manufactured with less than perfect yields. In alternative embodiments the redundancy aspect of the invention can be extended to any optical signal processing device, thus facilitating high availability optical signal processing.

Abstract: Systems and methods for transmitting data from one point to another by transparently converting the data from an initial form into an intermediate form for transport via a transmission or transport medium, and then converting the data back into the initial form, wherein the bit sequence and timing of the original data stream are reproduced. Timing data of the input data stream is identified and inserted into the data for transport. The timing data is extracted from the received data and used to reproduce the timing of the original data stream in the delivered data stream.

Abstract: A gain-clamped semiconductor optical amplifier includes a semiconductor optical amplifier for amplifying an inputted optical signal and outputting amplified spontaneous emission light, the amplified spontaneous emission light consisting of a first portion and a second portion, the first portion having a wavelength range to be amplified. The amplifier further includes a wavelength selective reflector for allowing the first portion of the amplified spontaneous emission light to pass through the wavelength selective reflector and reflecting the second portion of the amplified spontaneous emission light again to the semiconductor optical amplifier, thereby clamping the gain of the amplifier.

Abstract: A transmission system is provided that recognizes occurrence of a fault efficiently so that the workability and quality of service can be improved. An optical amplifier part amplifies an optical main signal. A fault occurrence recognizing part detects a pump light used for an opposing device via an optical fiber transmission line to which an optical main signal is sent by the repeater. If the pump light is not detected, the fault occurrence recognizing part recognizes occurrence of a fault. A light cutoff control part stops the optical amplifying part outputting an amplified signal so that the light cutoff control in only one of two directions is performed when a fault occurs.

Abstract: A digital signal channel bypass is provided as bypass around an optical network optical amplifier, in particular, an analog type optical amplifier, such as an EDFA, in an optical transport network or system. The digital signal bypass provides for an ability to maintain the existing optical amplifier OO amplification site while inserting a bypass that provides ultra low-cost OEO REGEN in a digital optical network (DON) utilizing both semiconductor electronic integrated circuit chips and semiconductor photonic integrated circuit (PIC) chips where all the optical components are in semiconductor integrated chip form providing 1R, 2R, 3R or 4R regeneration as well as other signal caring functionality. A salient feature of the digital signal bypass is to regenerate signals in the optical span that are outside the gain bandwidth of the EDFA or other such amplifier.

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: The invention provides an optical communication system (10) comprising a plurality of mutually interconnected bi-directional optical waveguide rings (20, 30, 40, 50, 60) in which radiation modulated with communication traffic propagates. The radiation is partitioned into 32 distinct wavebands. Interfaces (70, 80, 90, 100, 110, 120) are included in the system (10) where communication traffic propagating in the rings transfers from one ring to another. Each interface (70) is capable of providing an all-optical waveband reconfigurable communication link between the rings (20, 30, 40, 50, 60). At each interface (70), conversion of optical radiation to corresponding electrical signals is not required when transferring communication traffic from one ring to another, thereby providing the system (10) with a potentially larger communication bandwidth compared to conventional optical communication systems.

Abstract: An optical signal amplification device for outputting an output signal light which has the same wavelength as an input signal light and an intensity variation identical in phase with an intensity variation of the input signal light.

Abstract: The present invention regenerates optical signals in an intact optical state according to a low-speed optical clock. In one embodiment, an optical splitter applies a portion of optical pulse signals to a clock recovery circuit and the rest to an optical splitter. The optical splitter applies half of the input signal to an optical regenerator and the rest to another optical regenerator. The clock recovery circuit regenerates an electric clock signal with half the frequency of the input optical pulse and applies the clock to an optical clock pulse generator. The optical clock pulse generator generates an optical clock signal with half the frequency of the input optical pulse whose phase matches with that of the optical signal at the optical regenerator. An optical regenerator regenerates the optical signal from the optical splitter in an intact optical state. A polarization combiner combine the optical signals from the optical regenerators in mutually orthogonal polarization.

Abstract: This invention provides a dynamic interconnection system which allows to couple a pair of optical beams carrying modulation information. In accordance with this invention, two optical beams emanate from transceivers at two different locations. Each beam may not see the other beam point of origin (non-line-of-sight link), but both beams can see a third platform that contains the system of the present invention. Each beam incident on the interconnection system is directed into the reverse direction of the other, so that each transceiver will detect the beam which emanated from the other transceiver. The system dynamically compensates for propagation distortions preferably using closed-loop optical devices, while preserving the information encoded on each beam.

Abstract: All optical clock recovery includes a transmitter for generating an optical timing signal. The transmitter includes a semiconductor laser for the production of a dynamically synchronizable timing signal, the laser having an external resonator for feedback of the timing signal to the laser, the feedback having a delay time greater than a relaxation oscillation time for the laser, and the laser outputting an optical timing signal having a characteristic dynamic. The transmitter supplies the optical timing signal to a receiver configured to receive the timing signal and to synchronize to the laser on receipt of the timing signal, such that the receiver outputs a recovered timing signal having the characteristic dynamic.

Abstract: The present invention generally provides optical signal transmission system having an optical signal source, at least one optical signal regenerator in series communication with the optical signal source via an optical signal communications medium, a dispersion module in series communication with the at least one optical signal regenerator via the optical signal communications medium, and a receiver in serial communication with the dispersion module via the optical signal communications medium. The dispersion compensation module inserts an amount of lumped dispersion into the system, which operates to improve the signal transmission characteristics.

Abstract: A repeater apparatus (1001) is constituted from infrared transmitter sections (1s, 2s, 3s) and infrared receiver sections (1r, 2r, 3r) as well as connection control sections (1C, 2C, 3C) and further a repeater section (101), thereby attaining independent communications with the individual one of several associated equipments with respect to infrared communication apparatus of the direct emission type which supports only one-to-one (1-to-1) or one-to-several (1-to-N) communication schemes, thus enabling achievement of N-to-N communication forms by performing transfer of data information being received by each communication equipment to others.

Abstract: The present invention relates to a method for processing an optical signal is provided. An optical signal is input into an optical waveguide structure for providing a nonlinear effect. As a result, the optical signal undergoes chirping induced by the nonlinear effect. An output optical signal output from the optical waveguide structure is supplied to an optical bandpass filter to thereby extract components except a small-chirp component from the output optical signal. The optical bandpass filter has a pass band including a wavelength different from the wavelength of the optical signal. By extracting the components except the small-chirp component from the output optical signal in the form of pulse, it is possible to remove intensity fluctuations or accumulated noise especially at a top portion and/or a low-power portion of the pulse.

Abstract: An optical regenerator enabling matching of self-phase modulation induced spectral broadening and optical regenerator filter center wavelengths and bandwidths for different fiber dispersion values. The regenerator monitors the central part of an input signal spectrum at the output of a non-linear medium and suppresses the power at the center wavelength to allow for a constant spectral broadening for different fiber dispersion values. The regenerator utilizes a control filter to control a variable amplifier via a feedback loop, and the variable amplifier adjusts the power of the signal launched into the non-linear medium to ensure a sufficient self-phase modulation broadened spectrum.

Abstract: Inventive systems and methods for remotely controlling infrared controlled devices by using addressed radio frequency control signals. Radio frequency signals propagate through most obstructions to infrared control signals. Augmenting each control signal with an address allows for great selectivity in an environment with several transmitters and receivers.

Abstract: An optical submarine communication system has a land cable connected to a terminal apparatus which is installed on land near the seashore for transmitting an optical signal and electric power. The land cable is connected to an optical submarine cable through a beach manhole, and a repeater is connected to the optical submarine cable. The optical submarine communication system has a surge suppressor provided on the land cable, whereby a surge generated from the terminal apparatus side because of a lightning stroke or an insulation failure is suppressed and prevented from reaching and damaging the repeater.

Abstract: A synchronous optical regenerator applies intensity modulation and phase modulation. The phase modulation is effected after the intensity modulation by the crossed Kerr effect in a Kerr fiber. The clock used for the phase modulation is obtained by injecting a continuous wavelength into the intensity modulator. The regenerator therefore includes a multiplexer coupling continuous light with the signals transmitted, an intensity modulator modulating the signals transmitted and the continuous light, and a Kerr fiber phase modulating the transmitted signals by crossed phase modulation with the intensity-modulated continuous light. Applications include wavelength division multiplex transmission systems.

Abstract: An optical regenerator suitable for use with optical signals has two stages. An incoming optical signal to be regenerated passes first through a data division stage. This divides the optical data stream into a number of data streams at a bit rate lower than the original optical signal. These data streams then pass to a regeneration stage. In the regeneration stage, there are a number of optical gates. Each gate receives one of the optical data streams at its control input. An optical clock stream at the lower or at a multiple thereof passes through the optical gates. The outputs of these optical gates are connected in common to the optical output of the regenerator and provide a bit-interleaved regenerated optical data stream at the output.

Abstract: The present invention relates to a method for regenerating an optical signal suitable for WDM (wavelength division multiplexing). In this method, an optical signal is supplied to an optical waveguide structure (e.g., optical fiber) for providing a nonlinear effect. As a result, the optical signal undergoes chirp induced by the nonlinear effect. Then, an output optical signal output from the optical waveguide structure is supplied to an optical filter to thereby remove a small-chirp component from the output optical signal. By removing the small-chirp component from the output optical signal in the form of pulse, intensity fluctuations or accumulated noise especially at a top portion and/or a low-power portion of the pulse can be removed. Accordingly, the optical signal can be regenerated independently of the bit rate, pulse shape, etc. of the optical signal.

Abstract: A system and method for regenerating optical signals comprising a clock recovery circuit coupled to a transmission line, a first optical gating device having an input port coupled to the transmission line and a clock port coupled to the clock recovery circuit, and a second optical gating device having an input port coupled to a continuous wave (CW) laser and a clock port coupled to the output of the first optical gating device, wherein the optical gating devices may be terahertz optical asymmetric demultiplexers (TOADs).

Abstract: An on/off switchable source of a continuous optical signal at a respective wavelength (?2) is provided to be turned off when the wavelength (?1) of the modulated incoming signal corresponds to the respective wavelength (?2) generated by the source while turning said source on when the wavelength (?1) of the incoming signal differs from the source wavelength (?2). A Michelson interferometer is provided adapted to receive the incoming signal and the continuous optical signal generated by the source to produce an output signal. The Michelson interferometer is adapted to give rise to destructive viz. constructive interference when the incoming signal has first and second logical values, respectively. When the wavelength (?1) of the incoming signal, which is not generally known a priori, corresponds to the source wavelength (?2), the source is switched off and the output signal is a replica of the incoming signal regenerated at the interferometer.

Abstract: According to a PLL circuit of the present invention, an output of a phase comparator is adjusted according to a space-to-mark transition-probability of an input signal so that an output of a voltage controlled oscillator has a predetermined frequency and phase. Therefore, even when a phase of a timing clock is set other than at 0, an output of the PLL circuit can be kept at the set phase, irrespective of the space-to-mark transition-probability. By using the PLL circuit as such in an optical communication apparatus and an optical communication system, a discrimination point can be kept almost fixed, and therefore, it is possible to lower an error rate.

Abstract: A wavelength converter and a wavelength division-multiplexing optical communication apparatus automatically generate clock signals of a specified frequency that match send/receive digital signals and regenerates timing for the send/receive digital signals. The wavelength converter includes: optical/electrical signal converters (2A, 2B) that convert input optical signals into electric digital signals; clock generator circuits (4A, 4B) that automatically identify the transmission mode for digital signals and generate phase-synchronized clocks of a specified frequency that match the signal transmission mode; timing regeneration circuits (6A, 6B) that regenerate clock timing for the digital signals based upon the phase-synchronized clocks from the clock generator circuits; and electric/optical converters (3A, 3B) that convert the digital signals from the timing regeneration circuits into optical signals of a specified wavelength.

Abstract: A system for all-optical signal regeneration is provided, which makes it possible to exhibit desired intensity noise suppressing function with respect to pulsed input signal light without increasing the injection current of semiconductor optical amplifiers even if the magnitude of nonlinear phase shift of the input signal light is less than ?. The output light of the first delay interference unit is subjected to phase shift in the first nonlinear semiconductor waveguide and then, applied to the second delay interference unit along with the clock light. In the second delay interference unit, the first interfered light is generated from the output light while the second interfered light is generated from the clock light having an opposite logic to the input light. The second interfered light is subjected to phase shift by the first interfered light in the second nonlinear semiconductor waveguide and then, applied to the third delay interference unit.

Abstract: Optical regenerators are disclosed, one of which includes a splitter having an input signal input, and first and second outputs, where the first output is connected to a first input of an optical flip-flop that also includes an output. A first OAND gate includes a first input connected to the output of the optical flip-flop, and also includes a second input and an output. A second OAND gate has a first input connected to the second output of the splitter, and includes a second input and an output. A variable oscillator having an input and an output is arranged so that the output is connected to the second input of the second OAND gate and to the second input of the first OAND gate. Finally, a feedback controller has an input connected to the second OAND gate output, and an output connected to the variable oscillator input.

Abstract: An all-optical 3R regenerator (AO3R) and a method for using the AO3R to retime, reshape and retransmit an optical signal are described herein. The AO3R includes a polarizer that receives an input optical signal which is of unknown, potentially varying phase and outputs a stable polarized input optical signal. The AO3R also includes a first interferometer (e.g., interferometric converter module) that retimes and reshapes the polarized input optical signal and transmits the retimed and reshaped polarized input optical signal as a polarized output optical signal. The first interferometer is able to retime the polarized input optical signal with the aid of a laser and a clock recovery mechanism.

Abstract: A protection arrangement for an optical switching system includes protection switching for switch planes in the optical core and for ports in the tributary cards. For a multiple layer switch core protection is also provided between layers. A first layer is for switching optical channels. The protection switches used may be 1×N, 2×N or 3×N MEMS optical switches. The 1×N MEMS provides for protection switching. The 2×N MEMS provides protection switching and testing capability. The 3×N MEMS provides for protection switching, testing and backup of the protection switching. Application of these protection switches is shown in lambda plane switch cores, multiple layer switch cores and combined switch cores.

Abstract: A control system for an agile optical network uses constraint-based rules to minimize route validation computations required when the network is reconfigured. A hierarchical control structure facilitates admission control and insulates admission control from interaction with the physical layer of the network.

Abstract: An optical transmission system ensuring high-quality monitor control even if an optical fiber fault occurs. A monitor instruction sending unit sends a monitor instruction. An operating condition recognizing unit receives a response signal and recognizes the operating condition. A filtering unit filters the monitor instruction and the response signal. A monitor control unit monitors the operating condition of its own repeater in response to the monitor instruction, and generates resultant response information. A pump unit generates a pump light to cause Raman amplification within an optical fiber transmission medium. A regeneration control unit performs a regeneration control of the response signal to thereby create a regenerated signal. A modulation control unit modulates the pump light by the response information or the regenerated signal to thereby generate the response signal.

Abstract: A unique sensor is used to detect a transmission impairment that may have affected incoming optical channel signals. The sensor, more specifically, selects a group of the incoming channel signals and generates a first power signal, P0, over the selected group of signals and generates a second power signals, P1, over a weighted version of the selected group of channel signals. The sensor then generates, as a function of the first and second power signals, P0 and P1, a signal indicative of whether the particular transmission impairment affected the levels of individual ones of the incoming channel signals. If so, then control apparatus offsets the impairment accordingly.

Abstract: The device according to the present invention relates to phase conjugate conversion and wavelength conversion. This device includes a polarization beam splitter and a polarization maintaining fiber (PMF). The polarization beam splitter has first, second, and third ports. The first port is supplied with signal light including first and second polarization components respectively having first and second polarization planes orthogonal to each other, and with pump light. The first and second ports are coupled by the first polarization plane, and the first and third ports are coupled by the second polarization plane. The PMF has first and second ends, and has a polarization mode to be maintained between the first and second ends. The first end is optically connected to the second port so that the first polarization plane is adapted to the polarization mode, and the second end is optically connected to the third port so that the second polarization plane is adapted to the polarization mode.

Abstract: The invention consists of a system and method for regenerating and converting optical signals. The invention provides both “2R (i.e. reamplification and reshaping) and “3R” (i.e. reamplification, reshaping, and resynchronization (or retiming)) regeneration. The components of the inventive system include a tunable continuous wave (CW) laser source, an optical circulator, an semiconductor optical amplifier (SOA), and a spectral filter that has a very sharp cutoff frequency. In alternative embodiments, the filter may be replaced with an interleaver that passes several wavelengths. A single interleaver may be used by several of the optical regenerators/converters described herein. Each regenerator uses a separate wavelength that is associated with a passband frequency of the single interleaver. During counter-propagation in the SOA, a CW signal from the CW laser is chirped by bits in an input signal. The chirped signal is then output to the filter, which blocks the original CW signal.