摘要:
The present invention relates to the selected-wavelength tuning apparatus which is provided with an AOTF, a radio-frequency signal generator, an optical detector, and a controller for detecting lights emitted from the AOTF with the optical detector and for controlling a frequency of the radio-frequency generator so as to detect a light of predetermined wavelength.
摘要:
The present invention aims at providing a control method and a control apparatus for controlling the operation setting of an optical device with high accuracy, so as to reliably obtain characteristics according to a desired relationship to be set corresponding to a signal light, immediately after the control start. To this end, the control apparatus of the present invention comprises an optical coupler that branches a part of a main signal light input to the optical device, a monitoring optical device that operates in accordance with a control parameter same as for the optical device, and processes the monitor light branched by the optical coupler, a light receiver that receives the monitor light processed by the monitoring optical device, a detecting circuit that detects a relationship between the monitor light received by the light receiver, and the wavelength or optical power of the signal light, and a controlling circuit that adjust the control parameter for the optical device to control the operation setting, based on the relationship detected by the detecting circuit, so that characteristics of the optical device become capable of realizing the relationship to be set corresponding to the signal light.
摘要:
In a wavelength-division multiplexing transmission technique, a loss difference compensator for compensating a loss difference of an optical signal at each wavelength generated in a wavelength-division-multiplexed optical signal due to a wavelength-dependent transmission loss characteristic of an optical transmission line is disposed to the optical transmission line for transmitting the wavelength-division-multiplexed optical signal having a wide wavelength band in which optical signals at a plurality of wavelengths are wavelength-division-multiplexed to compensate the loss difference of the optical signal at each wavelength generated in the wavelength-division-multiplexed optical signal due to the wavelength-dependent transmission loss characteristic of the optical transmission line and a dispersion compensator, thereby transmitting the wavelength-division-multiplexed optical signal in a wide wavelength band for a long distance.
摘要:
An optical transmission device improved in quality and reliability of OADM function and permitting configuration of highly-flexible, economical OADM networks. A wavelength tunable filter variably selects a wavelength according to a control frequency. A filter controller applies the control frequency to the filter while scanning wavelength over an entire signal bandwidth, to detect, from a reference wavelength monitor signal supplied thereto, a reference control frequency which permits the filter to select a reference wavelength and according to which wavelength is matched. On receiving a wavelength selection request, the controller obtains a target control frequency from the reference control frequency and the position of a target wavelength relative to the reference wavelength, and applies the obtained frequency to the filter. A reference wavelength filter transmits the reference wavelength therethrough. A light-receiving element monitors the transmitted reference wavelength to generate the monitor signal.
摘要:
An object of the invention is to provide a wavelength locker which has a wider locking range than that of the wavelength locker in the prior art and which can cope with a plurality of wavelengths. The aforementioned objects are achieved by a wavelength locker, which comprises a periodic filter, a detecting part for detecting the intensity of a laser beam through the periodic filter, and a controlling part for controlling the wavelength of the laser beam to a desired wavelength in accordance with the output of the detecting part. In this wavelength locker, the FSR of the periodical filter is controlled according to space between the wavelengths, and refers to the number of wavelength to be locked, so that the characteristics corresponding to output wavelengths that vary in every period twice the space of wavelengths and are complementary to each other, can be obtained, and the locking range will become wider.
摘要:
An optical transmission device improved in quality and reliability of OADM function and permitting configuration of highly-flexible, economical OADM networks. A wavelength tunable filter variably selects a wavelength according to a control frequency. A filter controller applies the control frequency to the filter while scanning wavelength over an entire signal bandwidth, to detect, from a reference wavelength monitor signal supplied thereto, a reference control frequency which permits the filter to select a reference wavelength and according to which wavelength is matched. On receiving a wavelength selection request, the controller obtains a target control frequency from the reference control frequency and the position of a target wavelength relative to the reference wavelength, and applies the obtained frequency to the filter. A reference wavelength filter transmits the reference wavelength therethrough. A light-receiving element monitors the transmitted reference wavelength to generate the monitor signal.
摘要:
The present invention aims at providing a control method and a control apparatus for controlling the operation setting of an optical device with high accuracy, so as to reliably obtain characteristics according to a desired relationship to be set corresponding to a signal light, immediately after the control start. To this end, the control apparatus of the present invention comprises an optical coupler that branches a part of a main signal light input to the optical device, a monitoring optical device that operates in accordance with a control parameter same as for the optical device, and processes the monitor light branched by the optical coupler, a light receiver that receives the monitor light processed by the monitoring optical device, a detecting circuit that detects a relationship between the monitor light received by the light receiver, and the wavelength or optical power of the signal light, and a controlling circuit that adjust the control parameter for the optical device to control the operation setting, based on the relationship detected by the detecting circuit, so that characteristics of the optical device become capable of realizing the relationship to be set corresponding to the signal light.
摘要:
The present invention aims at providing a control method and a control apparatus for controlling the operation setting of an optical device with high accuracy, so as to reliably obtain characteristics according to a desired relationship to be set corresponding to a signal light, immediately after the control start. To this end, the control apparatus of the present invention comprises an optical coupler that branches a part of a main signal light input to the optical device, a monitoring optical device that operates in accordance with a control parameter same as for the optical device, and processes the monitor light branched by the optical coupler, a light receiver that receives the monitor light processed by the monitoring optical device, a detecting circuit that detects a relationship between the monitor light received by the light receiver, and the wavelength or optical power of the signal light, and a controlling circuit that adjust the control parameter for the optical device to control the operation setting, based on the relationship detected by the detecting circuit, so that characteristics of the optical device become capable of realizing the relationship to be set corresponding to the signal light.
摘要:
In an OADM system, an OADM device includes an AOTF. The AOTF can select an optional wavelength by changing the frequency of an RF signal to be applied. An optical signal having a specified wavelength can be dropped from a wavelength-multiplexed optical signal input from an input terminal, or a wavelength-multiplexed optical signal input from an add port can be multiplexed with a through optical signal. However, considering the increase in coherent cross talk, the AOTF should be exclusively used for dropping in an actual device configuration. Otherwise, a drop optical signal is branched by an optical coupler with the wavelength selected by a tributary station. Thus, the wavelength selected by the tributary station can be extracted by the AOTF from the through optical signal.
摘要:
In an OADM system, an OADM device includes an AOTF. The AOTF can select an optional wavelength by changing the frequency of an RF signal to be applied. An optical signal having a specified wavelength can be dropped from a wavelength-multiplexed optical signal input from an input terminal, or a wavelength-multiplexed optical signal input from an add port can be multiplexed with a through optical signal. However, considering the increase in coherent cross talk, the AOTF should be exclusively used for dropping in an actual device configuration. Otherwise, a drop optical signal is branched by an optical coupler with the wavelength selected by a tributary station. Thus, the wavelength selected by the tributary station can be extracted by the AOTF from the through optical signal.