Abstract: A tunable optical filter includes sequentially coupled Mach-Zehnder (MZ) interferometers. The first and last interferometers are configured to function as variable power splitter/combiner, whereas the middle interferometer or interferometers have unequal optical paths, creating a desired spectral response of the entire filter. The amplitude of the spectral response can be varied by varying the optical power splitting/combining ratios.

Abstract: A machine learning-based method for designing a high-strength high-toughness steel, including: (S1) obtaining data and filling in missing parts to form a data set; (S2) selecting feature data in the data set to form a standard data set; (S3) constructing two machine learning models of the high-strength high-toughness steel; (S4) completing training after the two models are evaluated to be qualified; (S5) finding frontier points, drawing a Pareto front, and distinguishing a known region and a feature space; (S6) in the feature space, setting a step for the feature data, drawing a grid space, and performing multiple training predictions on each grid point by using the models, to obtain predicted Gaussian distributions of two objectives; and (S7) searching for an expected improvement point through an efficient global optimization algorithm, and obtaining design parameter values of corresponding features.

Abstract: An optical amplifier includes two amplifier stages, a circulator and an output stage. The first amplifier stage amplifies an input optical signal, and provides a first-stage amplified optical signal that is to be outputted via the circulator to the second amplifier stage. The second amplifier stage amplifies the first-stage amplified optical signal, and outputs a second-stage amplified optical signal to the output stage. The output stage outputs a returned optical signal to the second amplifier stage, so that the second amplifier stage amplifies the returned optical signal, and provides a third-stage amplified optical signal that is to be outputted via the circulator and the output stage to serve as an output optical signal.

Abstract: 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.

Abstract: An experimental system for studying a refining mechanism and characteristic of a refiner plate, including a disc refiner unit, a first storage tank, a second storage tank, a circulating pump, a pipeline system, a detection device for measuring process variables including flow, pressure and temperature, and a data acquisition and control system. An operation parameter control system is provided to control an operation state of valves at different positions of the pipeline system to achieve the switching of the operation mode of the experimental system. The data acquisition and control system is configured to collect the parameters at different detection points. A method for operating the experimental system is also provided.

Abstract: 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.

Abstract: 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.

Abstract: A tunable optical dispersion compensator (TODC) for providing chromatic dispersion (CD) compensation of optical signals in a plurality of optical channels comprises: a plurality of CD compensation fibers; a tunable optical switch configurable for directing an optical signal in any of the plurality of optical channels to one of the plurality of fibers, dependent on a central wavelength of the optical signal; a first switch configurable for directing all signals in the plurality of optical channels to a first CD compensation fiber, in a first mode of operation, and for bypassing the first CD compensation fiber in a second mode of operation; and, the first CD compensation fiber, wherein the first switch and the tunable optical switch are connected so as to enable combining CD compensation provided by the first CD compensation fiber and CD compensation provided by any one of the plurality of CD compensation fibers.

Abstract: A tunable optical filter includes sequentially coupled Mach-Zehnder (MZ) interferometers. The first and last interferometers are configured to function as variable power splitter/combiner, whereas the middle interferometer or interferometers have unequal optical paths, creating a desired spectral response of the entire filter. The amplitude of the spectral response can be varied by varying the optical power splitting/combining ratios.

Abstract: An optical amplifier includes two amplifier stages, a circulator and an output stage. The first amplifier stage amplifies an input optical signal, and provides a first-stage amplified optical signal that is to be outputted via the circulator to the second amplifier stage. The second amplifier stage amplifies the first-stage amplified optical signal, and outputs a second-stage amplified optical signal to the output stage. The output stage outputs a returned optical signal to the second amplifier stage, so that the second amplifier stage amplifies the returned optical signal, and provides a third-stage amplified optical signal that is to be outputted via the circulator and the output stage to serve as an output optical signal.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for optical communications. In one aspect, an optical amplifier includes an input port, a wavelength division multiplexing fiber coupled to a pump source and to a bar-cross switch, a first gain stage optically coupled between a first port of the bar-cross switch and to an output port, the first gain stage including a first gain flattening filter, and a secondary gain stage optically coupled between a second port and a third port of the bar-cross switch, the secondary gain stage including a second gain flattening filter. When in a bar-state of the bar-cross switch, the secondary gain stage is bypassed. And when in a cross-state of the bar-cross switch, the secondary gain stage and the first gain stage are applied to an input light beam.

Abstract: A method for analyzing noise spectrum of an electronic device includes storing a waveform data including a plurality of data points, the waveform data is obtained by measuring a target signal from the electronic device, removing data points corresponding to a background noise fluctuation based on a smooth curve of the waveform data, data points considered candidates for peaks are extracted from the waveform data, classifying the extracted data points based on a distance between adjacent data points in order to discriminate a cluster of distant data points from data points closely positioned to dominant peaks, determining the dominant peaks based on the cluster of distant data points such that the data points closely positioned to the dominant peaks are ignored, each dominant peak corresponds to the characteristic of the electronic device, and outputting the dominant peaks as an analysis result for the electronic device.

Abstract: A method for analyzing noise spectrum of an electronic device includes storing a waveform data including a plurality of data points, the waveform data is obtained by measuring a target signal from the electronic device, removing data points corresponding to a background noise fluctuation based on a smooth curve of the waveform data, data points considered candidates for peaks are extracted from the waveform data, classifying the extracted data points based on a distance between adjacent data points in order to discriminate a cluster of distant data points from data points closely positioned to dominant peaks, determining the dominant peaks based on the cluster of distant data points such that the data points closely positioned to the dominant peaks are ignored, each dominant peak corresponds to the characteristic of the electronic device, and outputting the dominant peaks as an analysis result for the electronic device.

Abstract: A method for analyzing noise spectrum of an electronic device includes storing a waveform data including a plurality of data points, the waveform data is obtained by measuring a target signal from the electronic device, removing data points corresponding to a background noise fluctuation based on a smooth curve of the waveform data, data points considered candidates for peaks are extracted from the waveform data, classifying the extracted data points based on a distance between adjacent data points in order to discriminate a cluster of distant data points from data points closely positioned to dominant peaks, determining the dominant peaks based on the cluster of distant data points such that the data points closely positioned to the dominant peaks are ignored, each dominant peak corresponds to the characteristic of the electronic device, and outputting the dominant peaks as an analysis result for the electronic device.

Abstract: A tunable optical dispersion compensator (TODC) for providing chromatic dispersion (CD) compensation of optical signals in a plurality of optical channels comprises: a plurality of CD compensation fibers; a tunable optical switch configurable for directing an optical signal in any of the plurality of optical channels to one of the plurality of fibers, dependent on a central wavelength of the optical signal; a first switch configurable for directing all signals in the plurality of optical channels to a first CD compensation fiber, in a first mode of operation, and for bypassing the first CD compensation fiber in a second mode of operation; and, the first CD compensation fiber, wherein the first switch and the tunable optical switch are connected so as to enable combining CD compensation provided by the first CD compensation fiber and CD compensation provided by any one of the plurality of CD compensation fibers.

Abstract: 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.

Abstract: A method for analyzing noise spectrum of an electronic device includes storing a waveform data including a plurality of data points, the waveform data is obtained by measuring a target signal from the electronic device, removing data points corresponding to a background noise fluctuation based on a smooth curve of the waveform data, data points considered candidates for peaks are extracted from the waveform data, classifying the extracted data points based on a distance between adjacent data points in order to discriminate a cluster of distant data points from data points closely positioned to dominant peaks, determining the dominant peaks based on the cluster of distant data points such that the data points closely positioned to the dominant peaks are ignored, each dominant peak corresponds to the characteristic of the electronic device, and outputting the dominant peaks as an analysis result for the electronic device.

Abstract: A self-fit optical filter includes a dual fiber collimator, a diffraction grating for spatially dispersing the input light beam into a plurality of sub-beams, a cylindrical lens for focusing each of the sub-beams at a saturable absorber which becomes saturated dependent on intensity of light, and a reflector for reflecting the sub-beams back along their optical paths. A method of filtering includes: demultiplexing an input beam into a plurality of sub-beams having distinct center wavelengths, at least partially absorbing one or more of the sub-beams by using a saturable absorber while allowing other sub-beams to pass through, substantially unattenuated, and multiplexing the sub-beams into an output optical signal.

Abstract: A multi-stage optical amplifier has an input port for receiving an optical signal and a relatively short erbium doped optical fiber is coupled to the input port. Complex costly pump feedback is not required as a constant non-varying saturation pump is configured to provide non varying output power pump light of a predetermined wavelength suitable for excitation and full saturation of the erbium ions such that a full population inversion occurs. The length of the short erbium doped fiber and rare earth doping concentration of the erbium doped fiber is such that when pumped by said pump provides amplification of the optical signal of less than 15 dB. Locating a gain flattening filter after the short erbium doped optical fiber provides a relatively flat amplified output signal. Multi-stages of similar short erbium doped fibers pumped and saturated by the same pump signal economically provide increased amplification of the signal and filters after each state flatten the gain.

Abstract: A multi-stage optical amplifier has an input port for receiving an optical signal and a relatively short erbium doped optical fiber is coupled to the input port. Complex costly pump feedback is not required as a constant non-varying saturation pump is configured to provide non varying output power pump light of a predetermined wavelength suitable for excitation and full saturation of the erbium ions such that a full population inversion occurs. The length of the short erbium doped fiber and rare earth doping concentration of the erbium doped fiber is such that when pumped by said pump provides amplification of the optical signal of less than 15 dB. Locating a gain flattening filter after the short erbium doped optical fiber provides a relatively flat amplified output signal. Multi-stages of similar short erbium doped fibers pumped and saturated by the same pump signal economically provide increased amplification of the signal and filters after each state flatten the gain.