摘要:
The present invention relates to an optical transmitter and particularly to an optical transmitter including an external optical modulator such as Mach-Zehnder type optical modulator which modulates the light from a light source to output an optical signal with a drive voltage signal generated depending on an input signal According to the present invention is achieved by providing an optical modulator, which add weighting to operating point control signal in accordance with optical output level of the modulator.
摘要:
A plurality of pump light sources generate plural variations of pump light having different frequencies. A modulation circuit intensity-modulates the plural variations of pump light in the predetermined periods, respectively. A pump light pair whose frequency difference equals a Raman shift frequency are modulated such that they cannot simultaneously enters an emission state. A wavelength-multiplexer wavelength-multiplexes the plural variations of pump light modulated by the modulation circuit. A optical guide device guides the plural variations of pump light wavelength-multiplexed by the wavelength-multiplexer to an optical fiber.
摘要:
The present invention has an object to provide an optical transmission technology using Raman amplification wherein a supervisory signal transferred among a plurality of optical transmission apparatuses is superimposed on a main signal light by using a pumping light for Raman amplification. To this end, a Raman amplifier applied with the optical transmission method of the present invention, is provided with a supervisory signal superimposing section for superimposing a supervisory signal transferred among the optical transmission apparatuses on at least one of a plurality of pumping lights of different wavelengths to be supplied to a Raman amplification medium via a multiplexer from a pumping light generating section, thereby transmitting the main signal light propagated through the Raman amplification medium to be Raman amplified, which is superimposed with the supervisory signal.
摘要:
An optical sending apparatus of this invention includes a plurality of optical signal generating sections, a dispersion compensating section and a wavelength multiplexing section. The dispersion compensating section performs compensation with a predetermined chromatic dispersion value to at least one of polarized light generated by the optical signal generating sections while a predetermined state of polarized light is maintained. The wavelength multiplexing section combines output light outputted from the optical signal generating section with output light passing through the dispersion compensating section so that the polarized light of adjacent wavelengths crosses orthogonal to each other. The optical sending apparatus having such a construction can generate high-density WDM optical signals, the dispersion of which is compensated in advance, by a polarization crossing method.
摘要:
The present invention has an object to provide a technology for monitoring the quality of a WDM signal light, capable of quickly and accurately judging an occurrence of quality deterioration of signal light and a deterioration factor thereof. To this end, according to a quality monitoring apparatus of WDM signal light of the present invention, a part of the WDM signal light being propagated through an optical transmission path is branched as a monitor light, a signal light of one wavelength contained in the monitor light is selected as a channel to be measured. Then, the frequency of occurrences of bit error for the channel to be measured is repeatedly measured for a plurality of times, and whether or not the signal quality is deteriorated is judged, together with the deterioration factor based on the measurement results, and a control signal light for adjusting the signal light power according to the judgment result is transmitted to the optical transmission path, to achieve the improvement of a characteristic of the WDM signal light.
摘要:
A plurality of pump light sources generate plural variations of pump light having different frequencies. A modulation circuit intensity-modulates the plural variations of pump light in the predetermined periods, respectively. A pump light pair whose frequency difference equals a Raman shift frequency are modulated such that they cannot simultaneously enters an emission state. A wavelength-multiplexer wavelength-multiplexes the plural variations of pump light modulated by the modulation circuit. A optical guide device guides the plural variations of pump light wavelength-multiplexed by the wavelength-multiplexer to an optical fiber.
摘要:
A demodulator comprising an OR/NOR circuit, an exclusive OR/NOR circuit, and a delay circuit is disclosed as that capable of being suitably formed into a monolithic IC. Also, a polarization diversity receiver for coherent optical communication using the above demodulator as its constituent is disclosed as that having a smaller number of variable gain amplifiers and accordingly having the controlling circuit made simpler in structure.
摘要:
According to particular embodiments, determining paths in a network with asymmetric switches includes receiving a graph representing the network. Each asymmetric switch has defined degree connectivity between one or more pairs of degrees of the asymmetric switch. The graph is transformed to yield a transformed graph that accounts for the asymmetric switches. A routing process is applied to the transformed graph to yield one or more paths through the network.
摘要:
Systems and methods for multi-domain routing are provided. In some embodiments, a method for determining a path calculation from a source node to a destination node over a multi-domain network is provided. The method may include steps for receiving a predetermined sequence of domains for communicating information from the source node to the destination node, determining a link type for each of a plurality of links in the predetermined sequence of domains, modifying the link type of one or more of the plurality of links such that the plurality of links are unidirectional links towards a destination node, and determining a path along the predetermined sequence of domains based on the modified plurality of links.
摘要:
Systems and methods for determining multiple paths in a multi-domain network are provided. In some embodiments, a method for determining multiple paths in a network is provided. The method may include determining a first path between a source node and a destination node and determining a second path disjoint from the first path. In some embodiments, to determine the second path includes determining which ingress nodes are available in a domain that includes the destination node, where the available ingress nodes are not part of the first path, and implementing a disjoint path algorithm for each of the available ingress nodes. To determine the first path includes implementing forward path calculations.