Abstract: The signal relay apparatus has a plurality of photoelectric converters which convert an optical signal input from an electronic equipment (A-C) into an electric signal and outputs the same to the photoelectric converter (21-24), and which converts an electric signal input from another photoelectric converter and outputs the same to the corresponding electronic equipment; a plurality of switch circuits (31-34) which are provided at input and output ends of the electric signal of the photoelectric converter (21-23) and which are opened and closed to bypass the electric signal; and a power source supply section (41-43) which supplies a power source to the electronic equipment connected to the photoelectric converter.

Abstract: The present invention provides an all optical system for generating high rate modulated signals including: a generator for generating a first periodic signal at a first rate; an optical chopping device arranged to receive the first periodic signal for producing a second periodic signal having pulses that are narrower than the pulses of the first signal; a splitting device for receiving and splitting the second periodic signal into multiple images of the second periodic signal propagating along multiple optical paths, the multiple optical paths including optical modulators for modulating the images of the second periodic signal at a first rate to produce modulated signals; an interleaving device for receiving and interleaving the modulated signals to produce a stream of modulated signal having a second ratewhich is higher than the first rate.

Abstract: A bandwidth allocation device and a dynamic bandwidth allocation method are provided for differentiated classes of service in an Ethernet Passive Optical Network (EPON), which includes an optical line termination (OLT), an optical distribution network (ODN), and a plurality of optical network units (ONUs). The OLT includes a Multi-Point Control Protocol (MPCP) allocator, which includes a class-based queue state counter and a grant generator. The ONU includes an MPCP requester, which includes a class-based buffer counter and a request generator. The device and the method enable efficient utilization of network resources using class-based grant allocation.

Abstract: The optical transceiver module includes a housing and a plurality of components disposed at least partially within the housing. The components include an optical transmitter, an optical receiver, and a power controller integrated circuit (IC). The power controller IC is electrically coupled to at least one of the plurality of components. The power controller IC is configured to perform power supply functions for the optical transceiver module. Also, the power controller IC includes multiple voltage regulators providing power to the components at two or more voltages.

Abstract: Provided is a signal processor for converting a signal that converts a return to zero (RZ) signal into a non-return to zero (NRZ) signal, in which two 2R (re-amplifying, re-shaping) regenerators are connected in parallel between an input waveguide and an output waveguide with different lengths from each other. The 2R regenerator includes: two semiconductor optical amplifiers having different lengths from each other; and phase control means connected to a short semiconductor optical amplifier. The RZ signal input by a length difference of the waveguide is delayed by a time difference of a half of one bit so that the 2R regenerated NRZ signal can be obtained.

Abstract: Circuitry for monitoring the operation of an optoelectronic transceiver includes a sequence of interconnected signal processing circuits for processing an analog input signal and producing a digital result signal, where the analog signal represents one or more operating conditions of the optoelectronic transceiver. The sequence of signal processing circuits include gain circuitry for amplifying or attenuating the analog input signal by a gain value to produce a scaled analog signal, an analog to digital converter for converting the scaled analog signal into a first digital signal, and digital adjustment circuitry for digitally adjusting the first digital signal to produce the digital result signal. The digital adjustment circuitry includes shifting circuitry configured to shift an input digital signal in accordance with a shift value so as to produce a digital shifted signal. The digital result signal is stored in memory in predefined locations accessible by a host.

Abstract: An optical interleaver comprising a first optical 3×3 coupler for receiving a broadband optical signal at one input port thereof, a second 3×3 optical coupler, three differential delay lines connected in parallel port-to-port between output ports of the first optical 3×3 coupler and input ports of the second optical 3×3 coupler, an infinite impulse response (IIR) element disposed in each of two of the delay lines, and wherein optical signals travelling in the respective delay lines interfere at the second 3×3 coupler to produce three frequency shifted transmission channel output signals at respective output ports of the second 3×3 coupler.

Abstract: An optical WDM ring network includes at least two add/drop nodes connected in a ring path. The ring path comprises only a single optical fiber arranged for bidirectional traffic between the nodes. A 2×2 switch is used in one of the add/drop nodes for switching signals forwarded from the node to the other node to travel either on a first segment of the ring path or on a second, complementary segment of the ring path when required for protection purposes. Signals from the other node to the first node are issued to travel on both segments but the switch selects the actual segment from which the signals are received in the first node. The signals switches by the switch can be high priority signals used in protected channels communicated between the node and another node. On the segment from which the high priority signals are not received, low priority signals in non-protected channels can be communicated between the nodes, these channels also passing the switch.

Abstract: A programmable optical add/drop multiplexer (OADM) implements add/drop function of optical signals from a number of cross-connected optical systems while treating issues of coherent cross-talk, chromatic dispersion, slope of dispersion and amplitude equalization. Input WDM (wavelength division multiplexed) optical signals from a number of optical systems are each de-multiplexed into a number of optical path signal that are routed through switches and then multiplexed into a number of output WDM optical signals. Problems with coherent cross-talk in optical path signals are eliminated by introducing equivalent optical path lengths between paths through which the optical path signals propagate and by introducing dead-bands between consecutive optical path signals.

Abstract: A device and method to monitor and temperature compensate change in wavelength within a WDM optical communication system is disclosed. The device includes a laser diode for generating an optical signal for temperature monitoring, a first fiber Fabry-Perot interferometer sensor unit for generating a first sensor signal according to temperature by means of the optical signal, and a processor for monitoring temperature by means of the first sensor signal and an externally provided second sensor signal and equalizing waveforms of the two sensor signals with each other. The externally provided second sensor signal is provided by a remote node that includes a second fiber Fabry-Perot interferometer sensor unit for receiving the optical signal for temperature monitoring to generate the second sensor signal according to temperature, and a waveguide grating router unit for transmitting the second sensor signal to the optical line terminal.

Abstract: There is disclosed an optical wireless transmission apparatus in which a pilot light emitting section of a receiving/emitting section sends a pilot light in a wavelength region of 930 nm to 960 nm to a target apparatus, and a light receiving device having a light receiving sensitivity only to the same wavelength region of 930 nm to 960 nm receives light sent from the target apparatus. When the pilot light in the wavelength region of 930 nm to 960 nm is used, the pilot light is not obstructed by sunlight, and therefore optical axis adjustment can be mutually and exactly performed by the use of the pilot light sent from the target apparatus.

Abstract: A system and method for selecting optical amplifier placement in an optical network is disclosed. In one embodiment, a design tool is used to configure the optical add/drop multiplexers of each nose. For nodes with more than a small number of nodes there are a large number of possible optical amplifier configurations. Consequently, a subset of optical amplifier placement configurations is formed. In one embodiment an algorithm is used to eliminate from consideration optical amplifier configurations unlikely to have satisfactory minimum power characteristics. In one embodiment the quality of service of each configuration of the subset is analyzed to determine an optical amplifier placement configuration having a minimal number of amplifier and a desirable quality of service.

Abstract: The present invention relates to a WDM/SCM-PON and a media access control method for asymmetric packet communication in the same. In the WDM/SCM-PON, each SCM channel is classified and used as a link by adopting an SCM technique of subdividing a wavelength band of up/downstream data links between an OLT and ONTs into frequency bands, and the ONTs are formed so that a certain SCM channel is independently distributed not fixedly assigned. Accordingly, an inventory problem, which can be generated in WDM/SCM, is prevented before happens, asymmetric dynamic band allocation is performed, and asymmetric service of up/downstream transmission is supported. As a result, a band required for next generation service is dynamically provided, optical interference effect is minimized, and Ethernet compatibility is provided so that Ethernet service suitable for providing IP service can be accommodated.

Abstract: An optical frequency modulated transmitter includes a plurality of separately phased-controlled slave lasers, the outputs of which are combined to form a single output beam of the transmitter. A master optical oscillator outputs an optical signal for injection locking the plurality of slave lasers, the optical signal being frequency modulated directly in the master optical oscillator or externally thereof. Additionally, a method of frequency modulating an optical beam is disclosed using a plurality of slave lasers. Each of the slave lasers has an output, the outputs of which are combined to form the optical beam. The plurality of slave lasers is injection locked to an optical output of a master oscillator. The optical output of the master oscillator is frequency modulated before the optical output is applied to the plurality of lasers. Each slave laser of the plurality is phased controlled relative to other slave lasers of the plurality.

Abstract: A method and apparatus for mitigating intersymbol interference (ISI) from narrow-band optical filtering and improving transmission performance by filtering multichannel optical signals using an optical filter device that exhibits a desired loss ripple in the transmittance profile of the filter passband.

Abstract: A channel-growth plan for an optical transmission system selects channels such that the transients that result in the channels that survive a network failure, such as an upstream fiber cut, are either minimized or effectively handled by some transient-control technique. In one embodiment, the growth plan may try to keep post-transient surviving channel total power gain equal to the pre-transient total power gain. Alternatively, the growth plan may try to distribute the surviving channels uniformly over the pre-transient channel-frequency range. Other manifestations are to keep (1) the average power of the surviving channels substantially equal to the average power of the pre-transient channels or (2) the average power of the post-transient surviving channels substantially equal to the power level of a specified channel. Transient-control can be balanced with conventional low-cost and high-performance goals to provide an effective hybrid channel-growth plan.

Abstract: A method and system for mitigating effects of dispersion in an optical link. A pair of digital sample streams are synthesized representing a target optical E-field having a spectrum selected such that the convolution of the spectrum with itself yields a signal having beat terms that contain phase information of the target optical E-field. A complex optical modulator is driven in accordance with the computed orthogonal sample values.

Abstract: A switching apparatus for switching an optical channel overhead in an optical supervisory channel is disclosed. The switching apparatus can suppress a terminated optical channel defect occurred by a defect of upper layers of the optical channel or a defect of the optical channel transmitter and also can maintain the corresponding optical channel at the wavelength converted optical transport network system. Furthermore, an apparatus for forwarding an optical channel maintenance signal is disclosed too. The apparatus includes the switching apparatus and transmits only an add and drop optical channel maintenance signal information to the CPU and generate the LOS suppression signal with respect to the optical channel according to the occurrence of malfunction, thus directly transmitting the suppression signal to the corresponding optical channel unit.

Abstract: If no alarm is input from an optical receiver, an FEC decoder, or a client signal monitor, a control circuit controls a variable dispersion equalizer such that a transmission error becomes smaller using information on the number of error corrections obtained from the FEC decoder and fixes a dispersion equalization value in the event that the error becomes equal to or lower than a specified value. If the alarm information is input, the control circuit switches control over the variable dispersion equalizer from an ordinary control to a search mode control for searching an optimal dispersion equalization value in a wide range to thereby search the optimal dispersion equalization value at a higher speed.

Abstract: The present invention provides methods and devices for optical performance monitoring using co-located switchable fiber Bragg gratings (FBGs) in conjunction with a few detectors. This arrangement combines the merit of both tunable FBG filters and discrete detectors to achieve high spectral resolution, fast detection process and great dynamic range. By using parallel co-located FBGs in conjunction with a banded architecture, the tuning range of each FBG becomes much smaller (equivalent of ˜0.08% strain). As a result, not only does the update speed of the spectral characteristics for each channel become much faster, but it effectively eliminates the concern of FBG long-term reliability as well.