Abstract: An optical transmission apparatus includes: a wavelength selecting switch, including an input port and an output port having more ports than the input port, configured to perform an adjustment of a level of an optical signal from the input port to the output port; a first monitor configured to monitor the level of the optical signal at the input port unit; a second monitor configured to monitor the level of the optical signal at the output port unit; and a controller configured to control the wavelength selecting switch wherein the controller: calculates a virtual output value for the output port unit based on a first monitor result from the first monitoring unit, a second monitor result from the second monitoring unit, and a current adjustment value for the adjustment function; calculates a new adjustment value based on the virtual output value; and sets the new adjustment value to the adjustment.

Abstract: There is provided a transmission apparatus, which includes: a filter configured to pass an optical signal having a predetermined wavelength received via an optical fiber, a variable optical attenuator configured to attenuate a power level of the optical signal passed by the filter, a first measuring circuit configured to measure a first power of the optical signal before being passed by the filter, a second measuring circuit configured to measure a second power of the optical signal attenuated by the variable optical attenuator, a detector configured to detect a difference between the first power and the second power, and a controller configured to increase an attenuation factor of the variable optical attenuator when the difference is equal to or larger than a first predetermined value.

Abstract: An optical transmission apparatus includes: a wavelength selecting switch, including an input port and an output port having more ports than the input port, configured to perform an adjustment of a level of an optical signal from the input port to the output port; a first monitor configured to monitor the level of the optical signal at the input port unit; a second monitor configured to monitor the level of the optical signal at the output port unit; and a controller configured to control the wavelength selecting switch wherein the controller: calculates a virtual output value for the output port unit based on a first monitor result from the first monitoring unit, a second monitor result from the second monitoring unit, and a current adjustment value for the adjustment function; calculates a new adjustment value based on the virtual output value; and sets the new adjustment value to the adjustment.

Abstract: A control device for an optical channel monitor includes: at least one of a processor and a circuit configured to stop calibration of a measured wavelength when no peak intensity of a wavelength of incoming light is detected, the optical channel monitor measuring a light intensity at the measured wavelength, the at least one of processor and circuit configured to determine presence of a peak intensity in the incoming light when detecting the incoming light with a light intensity equal to or more than a given intensity, the at least one of processor and circuit configured to permit the calibration of the measured wavelength which has been stopped to be resumed when the wavelength peak is determined to be present.

Abstract: An optical wavelength multiplexing system includes transmission-side and reception-side optical wavelength multiplexers, and terminal devices, which are connected to each other by optical fiber cables. Optical wavelength converters in the transmission-side optical wavelength multiplexers are connected to ports respectively. The optical wavelength converter converts an input optical signal into an arbitrary preset wavelength to generate a converted optical signal. The port has a predetermined wavelength preset therein. Each optical power level of input converted optical signals is compared with each optical power level of optical signals of respective wavelengths set in the ports. When a difference is detected in the comparison result, it is determined that an optical wavelength converter is incorrectly connected to the port.

Abstract: A measurement apparatus for measuring an optical fiber transmission line used to connect to an opposite apparatus, the measurement apparatus includes a transmission part for generating a measurement packet used for measuring a length of a first and second optical fiber transmission line, and transmitting the measurement packet to the opposite apparatus through the first optical fiber transmission line, a reception part for detecting the measurement packet returned from the opposite apparatus that perform a loopback processing of the measurement packet through the second optical fiber transmission line, a calculation part for calculating a packet transmission time which is a processing time required from the generation of the measurement packet to the detection of the measurement packet, and a measurement part for performing a measurement control of the length of the first and second optical fiber transmission line based on the packet transmission time calculated by the calculation part.

Abstract: An identification apparatus for identifying an optical passive device product. The apparatus includes an optical input output monitor section for monitoring an optical input and an optical output of the optical passive device product respectively; a loss calculation section for calculating a loss in the optical passive device product based on a monitoring result of the optical input output monitor section; and a product identification section in which product information indicating a correspondence between a loss characteristic and a product has been stored in advance, and which identifies the optical passive device product by comparing the stored product information and the loss calculated by the loss calculation section.

Abstract: A measurement apparatus for measuring an optical fiber transmission line used to connect to an opposite apparatus, the measurement apparatus includes a transmission part for generating a measurement packet used for measuring a length of a first and second optical fiber transmission line, and transmitting the measurement packet to the opposite apparatus through the first optical fiber transmission line, a reception part for detecting the measurement packet returned from the opposite apparatus that perform a loopback processing of the measurement packet through the second optical fiber transmission line, a calculation part for calculating a packet transmission time which is a processing time required from the generation of the measurement packet to the detection of the measurement packet, and a measurement part for performing a measurement control of the length of the first and second optical fiber transmission line based on the packet transmission time calculated by the calculation part.

Abstract: The present invention provides an optical add/drop multiplexer including an optical power control unit for performing a control of an optical power by the unit of each signal light included in the wavelength multiplexed light, wherein the optical power control unit includes control logic for implementing a first control mode in which a transition to an automatic control of the optical power and release from the aforementioned control are carried out by comparing the optical power with a threshold value, and a second control mode in which a transition to an automatic control of the optical power is carried out based on control information of a notification by another of the optical add/drop multiplexers and release from the automatic control is carried out based on the comparison between the optical power and the threshold value.

Abstract: An optical transmission system with automatic startup functions to optimize the power level of optical signals entering each optical amplifier and operate those amplifiers in appropriate mode. In the process of starting up an optical transmission system, upstream and downstream optical transmission devices set up themselves under the coordination of their internal controllers. The downstream device controller adjusts its local variable optical attenuator by utilizing optical noise emission from a post-amplifier in the upstream optical transmission device, and it selects and sets a preamplifier unit to work in appropriate operating mode. The upstream device controller, on the other hand, selects and sets operating mode of its local post-amplifier unit. During this process, the upstream and downstream device controllers exchange messages over supervisory control channels to achieve the purpose.

Abstract: An identification apparatus for identifying an optical passive device product. The apparatus includes an optical input output monitor section for monitoring an optical input and an optical output of the optical passive device product respectively; a loss calculation section for calculating a loss in the optical passive device product based on a monitoring result of the optical input output monitor section; and a product identification section in which product information indicating a correspondence between a loss characteristic and a product has been stored in advance, and which identifies the optical passive device product by comparing the stored product information and the loss calculated by the loss calculation section.

Abstract: An optical transmission system with automatic startup functions to optimize the power level of optical signals entering each optical amplifier and operate those amplifiers in appropriate mode. In the process of starting up an optical transmission system, upstream and downstream optical transmission devices set up themselves under the coordination of their internal controllers. The downstream device controller adjusts its local variable optical attenuator by utilizing optical noise emission from a post-amplifier in the upstream optical transmission device, and it selects and sets a preamplifier unit to work in appropriate operating mode. The upstream device controller, on the other hand, selects and sets operating mode of its local post-amplifier unit. During this process, the upstream and downstream device controllers exchange messages over supervisory control channels to achieve the purpose.

Abstract: An optical wavelength multiplexing system includes transmission-side and reception-side optical wavelength multiplexers, and terminal devices, which are connected to each other by optical fiber cables. Optical wavelength converters in the transmission-side optical wavelength multiplexers are connected to ports respectively. The optical wavelength converter converts an input optical signal into an arbitrary preset wavelength to generate a converted optical signal. The port has a predetermined wavelength preset therein. Each optical power level of input converted optical signals is compared with each optical power level of optical signals of respective wavelengths set in the ports. When a difference is detected in the comparison result, it is determined that an optical wavelength converter is incorrectly connected to the port.

Abstract: An optical transmission system with automatic startup functions to optimize the power level of optical signals entering each optical amplifier and operate those amplifiers in appropriate mode. In the process of starting up an optical transmission system, upstream and downstream optical transmission devices set up themselves under the coordination of their internal controllers. The downstream device controller adjusts its local variable optical attenuator by utilizing optical noise emission from a post-amplifier in the upstream optical transmission device, and it selects and sets a preamplifier unit to work in appropriate operating mode. The upstream device controller, on the other hand, selects and sets operating mode of its local post-amplifier unit. During this process, the upstream and downstream device controllers exchange messages over supervisory control channels to achieve the purpose.

Abstract: The present invention provides an optical add/drop multiplexer including an optical power control unit for performing a control of an optical power by the unit of each signal light included in the wavelength multiplexed light, wherein the optical power control unit includes control logic for implementing a first control mode in which a transition to an automatic control of the optical power and release from the aforementioned control are carried out by comparing the optical power with a threshold value, and a second control mode in which a transition to an automatic control of the optical power is carried out based on control information of a notification by another of the optical add/drop multiplexers and release from the automatic control is carried out based on the comparison between the optical power and the threshold value.

Abstract: An optical transmission system with automatic startup functions to optimize the power level of optical signals entering each optical amplifier and operate those amplifiers in appropriate mode. In the process of starting up an optical transmission system, upstream and downstream optical transmission devices set up themselves under the coordination of their internal controllers. The downstream device controller adjusts its local variable optical attenuator by utilizing optical noise emission from a post-amplifier in the upstream optical transmission device, and it selects and sets a preamplifier unit to work in appropriate operating mode. The upstream device controller, on the other hand, selects and sets operating mode of its local post-amplifier unit. During this process, the upstream and downstream device controllers exchange messages over supervisory control channels to achieve the purpose.

Abstract: The present invention is directed to the provision of a wavelength division multiplexing optical transmission apparatus and, more particularly, to a wavelength division multiplexing optical transmission apparatus having high wavelength stability unaffected by the temperature characteristics, aging, etc. of an arrayed-waveguide grating (AWG) and its peripheral components.

Abstract: The present invention is directed to the provision of a wavelength division multiplexing optical transmission apparatus and, more particularly, to a wavelength division multiplexing optical transmission apparatus having high wavelength stability unaffected by the temperature characteristics, aging, etc. of an arrayed-waveguide grating (AWG) and its peripheral components.

Abstract: For regulating the vibration frequency of a tuning-fork vibrator to a desired frequency, the tuning-fork vibrator is regulated so that its vibration frequency may become a frequency lower than the desired frequency by a predetermined value, and then the tuning-fork vibrator is regulated so that a difference between proper vibration frequencies of both legs of the vibrator may become smaller than a predetermined value, and further, the vibrator is regulated so that the desired frequency may be reached, while maintaining the difference in the proper vibration frequency smaller than the predetermined value. In this way, the desired frequency can rapidly be attained.

Abstract: First and second color liquid crystal display elements of the negative guest-host type are disposed in adjacent and opposing relation to each other and the color liquid crystal display elements provide display in different colors, at least one of electrodes of each color liquid crystal display element having formed therein a display pattern. By the control of a changeover switch, an alternating drive voltage is applied from a drive circuit to one of the first and second color liquid crystal display elements to change the color of a background of the display in accordance with the control of the changeover switch.