Abstract: The present invention provides a fiber-cut detection method, apparatus, and system. When a fiber cut occurs, power of input signal light decreases quickly at a fiber-cut location. When the fiber-cut location is relatively far away from an amplifier, pump light consumption of the input signal light in the remaining fiber reduces due to reduction of the input signal light, which causes an increase of remaining pump optical power in the fiber and an increase of an actual gain value of the amplifier. A gain-locking function of the amplifier works, which decreases pump power of the pump light and maintains a gain of the amplifier unchanged basically. Output optical power of the amplifier decreases quickly with decrease of input optical power, and when power of an output optical signal decreases to power that is lower than preset power of the output optical signal, it is determined that a fiber cut occurs.

Abstract: A method for compensating for a signal error at a transmit end of an optical time domain reflectometer is provided. The method includes: detecting an actual signal sequence of a PN sequence sent by a transmitter to a measured optical fiber and an actual signal sequence of an optical signal and reflected back by the measured optical fiber and received by a receiver; obtaining a compensation value of the optical signal that attenuates in a process in which the optical signal is reflected by the measured optical fiber; computing an optical fiber attenuation curve function obtained through a current iteration; and determining, when determining that the optical fiber attenuation curve function obtained through the current iteration satisfies a given condition, performance of the measured optical fiber according to the optical fiber attenuation curve function obtained through the current iteration.

Abstract: An optical time domain reflectometer and a method for detecting an optical fiber are disclosed. In an embodiment the optical time domain reflectometer includes: a service signal generator, a signal coupler connected to the service signal generator, an electro-optical modulator connected to the signal coupler, a transmitter connected to the electro-optical modulator, a photoelectric detector connected to the transmitter, and an analog to digital converter connected to the photoelectric detector. The optical time domain reflectometer further includes: a digital signal processor, connected to the service signal generator, the signal coupler, and the analog to digital converter, and configured to generate compensation data and a PN code sequence, receive a sampled signal sent by the analog to digital converter, and calculate a first optical fiber function.

Abstract: A method for compensating for a signal error at a transmit end of an optical time domain reflectometer is provided. The method includes: detecting an actual signal sequence of a PN sequence sent by a transmitter to a measured optical fiber and an actual signal sequence of an optical signal and reflected back by the measured optical fiber and received by a receiver; obtaining a compensation value of the optical signal that attenuates in a process in which the optical signal is reflected by the measured optical fiber; computing an optical fiber attenuation curve function obtained through a current iteration; and determining, when determining that the optical fiber attenuation curve function obtained through the current iteration satisfies a given condition, performance of the measured optical fiber according to the optical fiber attenuation curve function obtained through the current iteration.

Abstract: The embodiments of the present invention disclose a method and an apparatus for determining a gain of a Raman optical amplifier and a Raman optical amplifier. The method includes: acquiring present gain parameter information of a Raman optical amplifier; and determining a present gain of a monitoring channel of the Raman optical amplifier according to the present gain parameter information and a correspondence between a gain of the monitoring channel of the Raman optical amplifier and gain parameter information. According to the method and apparatus for determining a gain of a Raman optical amplifier and the Raman optical amplifier that are in embodiments of the present invention, a present gain of a monitoring channel can be accurately determined; therefore, a gain spectrum of the Raman optical amplifier can be accurately monitored, and the gain of the Raman optical amplifier can be accurately adjusted to a target gain.

Abstract: An optical device with integrated Optical Time Domain Reflectometer (OTDR) functionality and method for the same is provided. The optical device includes a transmitter and an Optical Time Domain Reflectometer (OTDR) module, The transmitter is configured to generate an Optical Time Domain Reflectometer (OTDR)-modulated optical supervisory channel (OSC) signal by applying an OTDR modulation to an optical supervisory channel (OSC) signal using an OTDR signal and to transmit the OTDR-modulated OSC signal. The OTDR module is configured to generate the OTDR signal, to monitor a returned light signal, to determine transmitter noise compensation information, and to generate OTDR trace information using transmitter noise compensation information and the monitored returned light signal.

Abstract: An optical time domain reflectometer and a method for detecting an optical fiber are disclosed. In an embodiment the optical time domain reflectometer includes: a service signal generator, a signal coupler connected to the service signal generator, an electro-optical modulator connected to the signal coupler, a transmitter connected to the electro-optical modulator, a photoelectric detector connected to the transmitter, and an analog to digital converter connected to the photoelectric detector. The optical time domain reflectometer further includes: a digital signal processor, connected to the service signal generator, the signal coupler, and the analog to digital converter, and configured to generate compensation data and a PN code sequence, receive a sampled signal sent by the analog to digital converter, and calculate a first optical fiber function.

Abstract: The present invention discloses a method and an apparatus for determining a gain of a Raman optical amplifier and a Raman optical amplifier. The method includes: acquiring present gain parameter information of a Raman optical amplifier; and determining a present gain of a monitoring channel of the Raman optical amplifier according to the present gain parameter information and a correspondence between a gain of the monitoring channel of the Raman optical amplifier and gain parameter information. According to the method and apparatus for determining a gain of a Raman optical amplifier and the Raman optical amplifier that are in embodiments of the present invention, a present gain of a monitoring channel can be accurately determined; therefore, a gain spectrum of the Raman optical amplifier can be accurately monitored, and the gain of the Raman optical amplifier can be accurately adjusted to a target gain.

Abstract: The present invention provides a fiber-cut detection method, apparatus, and system. When a fiber cut occurs, power of input signal light decreases quickly at a fiber-cut location. When the fiber-cut location is relatively far away from an amplifier, pump light consumption of the input signal light in the remaining fiber reduces due to reduction of the input signal light, which causes an increase of remaining pump optical power in the fiber and an increase of an actual gain value of the amplifier. A gain-locking function of the amplifier works, which decreases pump power of the pump light and maintains a gain of the amplifier unchanged basically. Output optical power of the amplifier decreases quickly with decrease of input optical power, and when power of an output optical signal decreases to power that is lower than preset power of the output optical signal, it is determined that a fiber cut occurs.

Abstract: An optical device with integrated Optical Time Domain Reflectometer (OTDR) functionality and method for the same is provided. The optical device includes a transmitter and an Optical Time Domain Reflectometer (OTDR) module, The transmitter is configured to generate an Optical Time Domain Reflectometer (OTDR)-modulated optical supervisory channel (OSC) signal by applying an OTDR modulation to an optical supervisory channel (OSC) signal using an OTDR signal and to transmit the OTDR-modulated OSC signal. The OTDR module is configured to generate the OTDR signal, to monitor a returned light signal, to determine transmitter noise compensation information, and to generate OTDR trace information using transmitter noise compensation information and the monitored returned light signal.