ACCELINK TECHNOLOGIES CO., LTD.

Disclosed are an online program update method and device for an optical amplifier. The method comprises: when a program update instruction is sent, a Microcontroller Unit MCU receiving update programs of MCU and a programmable logic device FPGA, storing them in a program memory device, and sending an update instruction to FPGA; FPGA terminating operations of a digital-to-analog converter DAC according to the instruction and a current state remaining unchanged; MCU loading new codes of MCU and FPGA while DAC remains in state of halting refreshing; and after MCU and FPGA run the new codes, reading previously stored data, and starting switching from a previous operation state to enter normal operation state. On basis of conventional optical amplifier control, the invention combines characteristics of MCU and FPGA, and ensures uninterrupted service of optical amplifiers, achieving smooth transition of service, thereby improving stability and reliability of whole optical communications systems.

An optical circuit includes: a multicast-and-select (MCS) switch and multiple optical selective devices coupled to output ports of the MCS switch. The selective devices may select a single optical channel by blocking some of wavelengths of light passing therethrough and passing at least one other wavelength. The selective devices may be wave blockers or tunable optical filters. The optical circuit further includes an optical amplifying array, wherein each amplifier has an input port optically coupled to one of the selective devices. At least some of the amplifiers have pump light ports for receiving at least a portion of the pump light from one or more laser pumps or from another of the optical amplifiers, wherein the pumps are capable of providing pump light sufficient to fully saturate all of the rare earth doped optical fibers in the array.

Provided by the embodiments of the present invention are a remote optical fiber dispersion compensation device and method, the dispersion compensation device comprising: a distance measurement module, used for measuring a remote distance to a remote access optical fiber; a channel monitoring module, used for monitoring the spectral power of a transmission service wavelength channel; and a remote optical fiber dispersion power equalization module, used for compensating the dispersion of a transmission service signal and adjusting the insertion loss of the wavelength channel according to the measured remote distance of the remote access optical fiber and the monitored spectral power of the transmission service wavelength channel. By employing the embodiments of the present invention, compensation amounts of different channels may be flexibly selected by means of a wavelength selection switch, dispersion may be compensated for remote optical fiber transmission and the insertion loss may be adjusted for different channels by presetting dispersion compensation optical fibers of different lengths, thus achieving compensation and equalization of dispersion and power difference introduced by remote optical fibers of different lengths.

The present disclosure relates to optical communications, and in particular, to a DWDM remote pumping system for improving an OSNR. The system includes remote pumping gain unit, preamplifier, and gain flattening filter sequentially connected. Remote pumping gain unit and preamplifier are cascaded one behind the other as a whole amplifier. Gain flattening filter is disposed at the preamplifier's output end. In the system, remote gain unit and preamplifier which have large impact on the OSNR of the entire system are optimally designed as a whole amplifier. In remote gain unit, gain flattening filter originally disposed between two erbium-doped fiber segments is moved back to preamplifier's output end for significant improvement of gain and noise figures of the remote gain unit while ensuring gain flatness of the entire transmission system, thus effectively improving the entire system's OSNR, improving operation stability and reliability, effectively reducing bit error rate, and facilitating system maintenance.

The present disclosure relates to a technical field of optical communication, and provides a method and an apparatus for determining maximum gain of Raman fiber amplifier. Wherein the method includes obtaining transmission performance parameters of a current optical fiber transmission line; respectively obtaining impact factors A 1 , A 2 , A 4 according to a distance between a joint and a pump source, a fiber loss coefficient, and a fiber length included in the transmission performance parameters; calculating a joint loss value Att Aeff according to a distance between a joint and a pump source, a fiber loss coefficient, and looking up impact factor A 3 according to Att Aeff ; determining an actual maximum gain which may actually be achieved by the Raman fiber amplifier according to A 1 , A 2 , A 3 , A 4 . The actual maximum gain obtained in the present disclosure is the maximum gain that may be achieved over all input power ranges, and the original signal in system is kept to operate at a fixed gain, such that a gain locking effect is realized, and fluctuation of existing transmission signal power caused by signal change in transmission fiber link is avoided.

The present invention relates to the field of optical communication, and particularly to a balanced pumping L-band optical fiber amplifier comprising a first erbium-doped optical fiber, a second erbium-doped optical fiber, an absorbing erbium-doped optical fiber and at least two pumping lasers, the first erbium-doped optical fiber, the second erbium-doped optical fiber and the absorbing erbium-doped optical fiber being sequentially arranged in this order, and the at least two pumping lasers providing pumping light; wherein the first erbium-doped optical fiber and the second erbium-doped optical fiber both are injected with forward pumping light and backward pumping light, and the absorbing erbium-doped fiber is arranged downstream of the second erbium-doped optical fiber to absorb amplified spontaneous emission (ASE) generated in the amplifier. In the present invention, bidirectional pumping 1s applied in the first and last erbium-doped fibers in the optical path, and an erbium-doped optical fiber that has no pumping injection is added to absorb the ASE. Thus, the pumping conversion efficiency is greatly improved, the nonlinear four-wave mixing effect is reduced, and the problem that the L-band optical fiber amplifier has a high noise when utilizing the backward pumping 1s solved. Meanwhile, the noise figure and the manufacturing cost of the amplifier are reduced.

A method for realizing precise gain control for a hybrid fibre amplifier, and a hybrid fibre amplifier, in which by an erbium-doped fibre amplifier firstly outputting a constant power, a comparable source signal optical power is provided for a raman fibre amplifier of a next stage. A feedback for the gain control may be formed by comparing a source signal optical power calculated after starting pumping of the Raman fibre amplifier and a source signal optical power detected after pumping stops, thereby greatly improving gain control precision of the Raman fibre amplifier. Moreover, the erbium-doped fibre amplifier parts of all the hybrid fibre amplifiers may simultaneously output a constant optical power, and the Raman amplifier parts of all the hybrid fibre amplifiers may simultaneously start calibration, so that the time for starting operation of the entire system may be improved greatly.

Disclosed are a method, device and system for dynamically controlling a gain of a Raman optical fiber amplifier. The method comprises: determining whether a target gain falls within a gain mask range; if the target gain falls within the gain mask range, directly locking a gain to the target gain; and if the target gain falls outside the gain mask range, locking the gain to a corresponding maximum gain in the gain mask range, and gradually increasing the locked gain according to a preset first step length until the target gain is reached or until at least one pump laser reaches a maximum output power. The invention enables an optical fiber amplifier to respond quickly to a change in an input optical signal, ensures gain stability, and ensures that no power overshoot or undershoot occurs in the non-switched optical channels in an optical path. Moreover, the invention minimizes an amount of time required to complete switching between gains.

The present invention relates to technical field of communications and provides a method and a device for site selection for a monitoring station. The method comprises acquiring a site list comprising multiple relay stations and a connection relationship of optical cables among the relay stations; sequentially setting each relay station to be a starting site, and traversing the relay stations in the site list according to a preset coverage range from the starting site, and determining a set of uncovered relay stations corresponding to each starting site; according to a preset intersection base, traversing the set of relay stations that cannot be covered corresponding to each starting site to get an intersection, and determining one or more relay stations corresponding to a set of whose intersection result is empty as a target monitoring station. The method improves efficiency and accuracy of site selections and has wide applicability.

Provided by the embodiments of the present invention are a remote optical fiber dispersion compensation device and method, the dispersion compensation device comprising: a distance measurement module, used for measuring a remote distance to a remote access optical fiber; a channel monitoring module, used for monitoring the spectral power of a transmission service wavelength channel; and a remote optical fiber dispersion power equalization module, used for compensating the dispersion of a transmission service signal and adjusting the insertion loss of the wavelength channel according to the measured remote distance of the remote access optical fiber and the monitored spectral power of the transmission service wavelength channel. By employing the embodiments of the present invention, compensation amounts of different channels may be flexibly selected by means of a wavelength selection switch, dispersion may be compensated for remote optical fiber transmission and the insertion loss may be adjusted for different channels by presetting dispersion compensation optical fibers of different lengths, thus achieving compensation and equalization of dispersion and power difference introduced by remote optical fibers of different lengths.