Abstract: In order to provide technologies for implementing a control light receiving function and a signal light monitoring function by means of a simple configuration, this light control device includes: a wavelength-variable filter having a variable transmissive wavelength for transmitting input light; a photoelectric converter for converting output light from the wavelength-variable filter into an electric signal; and a controller for setting a transmissive wavelength and controlling a communication device on the basis of an electric signal corresponding to the transmissive wavelength.

Abstract: A variable optical BPF allows a signal light of a specified wavelength band in a signal light including reference signal lights to pass through. A light receiving unit outputs a level signal indicating a level of the signal light having passed through the variable optical BPF. A control unit refers to a wavelength table held in advance, instructs a wavelength band that passes through the variable optical BPF, and obtains a spectrum of the signal light having passed through the variable optical BPF using the wavelength table and the level signal. The control unit detects a wavelength drift between a center wavelength of the wavelength band instructed to the variable optical BPF to cause the reference signal lights to pass through and center wavelengths of peaks corresponding to the reference signal lights in the spectrum, and updates the wavelength table to corrects the detected wavelength drift.

Abstract: A light supply apparatus includes a second optical coupler, two first optical couplers, and excitation laser modules (light output units). Each of the first optical couplers is configured to have four input ports and four output ports. The second optical coupler is configured to have two input ports and two output ports. One of the input ports of the one first optical coupler is connected to one of the output ports of the second optical coupler. One of the input ports of the other first optical coupler is connected to another one of the output ports of the second optical coupler.

Abstract: A variable optical BPF allows a signal light of a specified wavelength band in a signal light including reference signal lights to pass through. A light receiving unit outputs a level signal indicating a level of the signal light having passed through the variable optical BPF. A control unit refers to a wavelength table held in advance, instructs a wavelength band that passes through the variable optical BPF, and obtains a spectrum of the signal light having passed through the variable optical BPF using the wavelength table and the level signal. The control unit detects a wavelength drift between a center wavelength of the wavelength band instructed to the variable optical BPF to cause the reference signal lights to pass through and center wavelengths of peaks corresponding to the reference signal lights in the spectrum, and updates the wavelength table to corrects the detected wavelength drift.

Abstract: An object is to provide a monitoring signal light output apparatus capable of transmitting a monitoring signal light with a simple configuration. An optical demultiplexer (11) is inserted into an optical fiber (F1) and demultiplexes a monitoring signal light (M1) transmitted through the optical fiber (F1). A SOA (13) amplifies and modulates the monitoring signal light (M1) separated by the optical demultiplexer (11). A control unit (15) outputs a signal (S1) indicating a state of a submarine apparatus. A SOA drive unit (14) outputs a drive signal (S2) to the SOA (13) in response to the signal (S1) to perform a modulation operation of the monitoring signal light (M1). An optical multiplexer (17) multiplexes the monitoring signal light (M1) amplified and modulated by the SOA (13) into the signal light transmitted by the optical fiber (F1). The monitoring signal light output apparatus is mounted on the submarine apparatus.

Abstract: An object is to respectively provide excitations light from a plurality of light sources to an odd number of fiber pairs. Optical amplifiers are disposed in three fiber pairs including two optical fibers through which optical signals are transmitted, respectively. The optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. An optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. In optical multiplexers/demultiplexers, one input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, the other input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, one output is alternatively connected to one optical fiber of any one of the three pairs, and the other output is alternatively connected to the other optical fiber of any one of the three pairs.

Abstract: An optical add/drop multiplexer includes: a first wavelength selector configured to output an optical signal of each wavelength of an inputted first wavelength multiplexed signal while selecting a path for each wavelength; a measurement circuit configured to measure optical power of an inputted optical signal; and a second wavelength selector including a circuit configured to output an optical signal of each wavelength of the first wavelength multiplexed signal while selecting a path for each wavelength, in place of the first wavelength selector when an abnormality occurs in the first wavelength selector, and a circuit configured to output an inputted second wavelength multiplexed signal for each prescribed wavelength unit to the measurement circuit when the first wavelength selector normally operates.

Abstract: An object is to respectively provide excitations light from a plurality of light sources to an odd number of fiber pairs. Optical amplifiers are disposed in three fiber pairs including two optical fibers through which optical signals are transmitted, respectively. The optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. An optical multiplexer/demultiplexer has inputs connected to light sources and three outputs. In optical multiplexers/demultiplexers, one input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, the other input is alternatively connected to any one of the three outputs of the optical multiplexer/demultiplexer, one output is alternatively connected to one optical fiber of any one of the three pairs, and the other output is alternatively connected to the other optical fiber of any one of the three pairs.

Abstract: An optical communication device includes equal branching optical system (301), to which a first excitation light beam (P1) and a second excitation light beam (P2) are input, generates a plurality of equally branched light beams (P12), an unequal branching optical system (401), to which a third excitation light beam (Padd) is input, generates a plurality of unequally branched light beams (Pm, Pn), the equally branched light beams (P12) and the first unequally branched light beam (Pm) are input to a first equal branching coupler (302), which outputs output branched light beams (P12m) as excitation light for optical fiber amplifiers (100, 200) for a first wavelength band, the equally branched light beams (P12) and the second unequally branched light beam (Pn) are input to a second equal branching coupler (303), which outputs output branched light beams (P12n) as excitation light for optical fiber amplifiers (101, 201) for a second wavelength band.

Abstract: To address the problem of an increase in the complexity of the structure of a ROADM device using a WSS device when WSS is multiplexed or made redundant, an optical transmission device includes an optical add-drop multiplexer which produces an output by multiplexing/demultiplexing arbitrary wavelengths into or from first signal light and second signal light that are input, and a multiplexer/demultiplexer to which the input of the first signal light and the second signal light is switched, characterized in that the multiplexer/demultiplexer is transmissive to a predetermined wavelength band of the first signal light, and produces an output by multiplexing/demultiplexing the first signal light that has been transmitted and the second signal light.

Abstract: In order to achieve a highly reliable reconfigurable optical add/drop multiplexing (ROADM) device, this optical multiplexing and demultiplexing device is provided with: a first wavelength selection switch which multiplexes, by wavelength, and outputs optical signals contained in a first wavelength multiplexed optical signal; a second wavelength selection switch which multiplexes, by wavelength, and outputs optical signals contained in a second wavelength multiplexed optical signal; an optical switch which, on the basis of the states of the first wavelength selection switch and the second wavelength selection switch, outputs the first wavelength multiplexed optical signal and the second wavelength multiplexed optical signal to the first wavelength selection switch or the second wavelength selection switch; and a first coupler which couples together the output from the first wavelength selection switch and the output from the second wavelength selection switch.

Abstract: To provide an optical communication technology that brings flexibility to ROADM systems. An optical communication device according to the present invention drops and adds an optical signal from and to wavelength-division multiplexed optical signals that are transmitted on a main path between network terminal stations, the device including: first means and second means capable of selecting an optical signal of a predetermined wavelength from inputted optical signals and of outputting the selected optical signal; third means for splitting optical signals inputted from a first terminal station on the main path into the first means and the second means; fourth means for splitting optical signals inputted from a branch path in the network into the first means and the second means; and fifth means capable of selectively outputting to a second terminal station on the main path either an optical signal outputted by the first means or an optical signal outputted by the second means.

Abstract: In order to achieve a highly reliable reconfigurable optical add/drop multiplexing (ROADM) device, this optical multiplexing and demultiplexing device is provided with: a first wavelength selection switch which multiplexes, by wavelength, and outputs optical signals contained in a first wavelength multiplexed optical signal; a second wavelength selection switch which multiplexes, by wavelength, and outputs optical signals contained in a second wavelength multiplexed optical signal; an optical switch which, on the basis of the states of the first wavelength selection switch and the second wavelength selection switch, outputs the first wavelength multiplexed optical signal and the second wavelength multiplexed optical signal to the first wavelength selection switch or the second wavelength selection switch; and a first coupler which couples together the output from the first wavelength selection switch and the output from the second wavelength selection switch.

Abstract: To provide an optical communication technology that brings flexibility to ROADM systems. An optical communication device according to the present invention drops and adds an optical signal from and to wavelength-division multiplexed optical signals that are transmitted on a main path between network terminal stations, the device including: first means and second means capable of selecting an optical signal of a predetermined wavelength from inputted optical signals and of outputting the selected optical signal; third means for splitting optical signals inputted from a first terminal station on the main path into the first means and the second means; fourth means for splitting optical signals inputted from a branch path in the network into the first means and the second means; and fifth means capable of selectively outputting to a second terminal station on the main path either an optical signal outputted by the first means or an optical signal outputted by the second means.

Abstract: [Problem] In an optical amplifier, the excitation light level of an excited laser diode decreases, or, when the output of an excitation light is stopped, a backup excited laser diode is operated, and therefore the current consumption increases. [Solution] This optical amplifier is provided with multiple excitation laser diodes, a first current control element, a second current control element, and control means. The excitation laser diodes oscillate excitation light, the excitation light being inputted to an optical fiber amplifier. The first current control element controls a current flowing in the excitation laser diodes. The second current control element controls a current flowing in at least one of the excitation laser diodes. The control means controls the first current control element and the second current control element.

Abstract: Even when some light emitting elements among the plurality of light emitting elements fail, a repeater, can be continuously operated. Means for solving the problems A light source unit 50 which includes a plurality of pumping light source modules 51 (51a to 51d) which include light emitting elements 52 (52a to 52d) for emitting an excitation light and monitor elements 53 (53a to 53d) for monitoring the excitation lights of the light emitting elements 52 (52a to 52d), respectively, a distribution unit 40 which combines the excitation lights from the plurality of pumping light source modules 51 (51a to 51d) and distributes it, and a control unit 60 which supplies a drive current flowing serially through the plurality of light emitting elements 52 (52a to 52d) in a plurality of excitation modules 51 (51a to 51d) are included.

Abstract: In an optical amplifier, the excitation light level of an excited laser diode decreases, or, when the output of an excitation light is stopped, a backup excited laser diode is operated, and therefore the current consumption increases. [Solution] This optical amplifier is provided with multiple excitation laser diodes, a first current control element, a second current control element, and control means. The excitation laser diodes oscillate excitation light, the excitation light being inputted to an optical fiber amplifier. The first current control element controls a current flowing in the excitation laser diodes. The second current control element controls a current flowing in at least one of the excitation laser diodes. The control means controls the first current control element and the second current control element.

Abstract: Even when some light emitting elements among the plurality of light emitting elements fail, a repeater, can be continuously operated. Means for solving the problems A light source unit 50 which includes a plurality of pumping light source modules 51 (51a to 51d) which include light emitting elements 52 (52a to 52d) for emitting an excitation light and monitor elements 53 (53a to 53d) for monitoring the excitation lights of the light emitting elements 52 (52a to 52d), respectively, a distribution unit 40 which combines the excitation lights from the plurality of pumping light source modules 51 (51a to 51d) and distributes it, and a control unit 60 which supplies a drive current flowing serially through the plurality of light emitting elements 52 (52a to 52d) in a plurality of excitation modules 51 (51a to 51d) are included.

Abstract: An optical module includes a circuit board mounted with a light receiving element, and a waveguide board in which a waveguide is formed. The circuit board is made of a flexible material, and has transmissivity for light having a wavelength received by the light receiving element. A circuit pattern part is formed on a surface on one side of the circuit board, and the light receiving element is mounted on the circuit pattern part. An optical filter part that transmits the light having the wavelength received by the light receiving element and that reflects light having other wavelengths, is formed on a surface on the other side of the circuit board by depositing a dielectric multilayer film. The waveguide board is connected to the optical filter part. In the light receiving element, a light receiving layer is disposed at a position outside from a region where the circuit pattern part is formed.

Abstract: It is to prevent optical coupling of the light that makes incident on an optical film obliquely and a light-receiving part of a light-receiving element, in an optical system where the light-receiving element is disposed on an emission-face side of the optical film that is formed with a dielectric multilayer film. A light-shielding film layer is formed on the light-receiving element itself. That is, the light-shielding film layer is formed on the incident-face side of the light-receiving element, and an opening is formed on the light-shielding film layer at a position that corresponds to a p-region. The size of the opening is so set that only the parallel light or the light close to that state is optically coupled with the p-region, based on a distance from the incident face to the p-region of the light-receiving part region.