Abstract: The present invention provides a method for synthesizing high-purity carbon nanocoils based on a composite catalyst formed by multiple small-sized catalyst particles, and belongs to the technical field of material preparation. In the present invention, Fe—Sn—O nanoparticles with sizes of less than 100 nm prepared by chemical or physical methods are used as catalysts, and stacked and made into contact in a simple manner, and then carbon nanocoils are efficiently synthesized from the prepared catalysts by a thermal chemical vapor deposition method. The method provided by the present invention has simple process and low cost. In addition, the preset invention discloses a novel carbon nanocoil growth mechanism, which makes the prepared catalyst for carbon nanocoil growth more efficient and easier for industrialized mass production.

Abstract: The present invention discloses a method and an apparatus for measuring quality parameters of optical transmission channels. The apparatus comprises: a tunable optical filter for receiving an optical signal, performing wavelength or optical carrier demultiplexing on the optical signal, and out-of-band ASE noise suppression; an optical coherent receiver connected to the tunable optical filter, for performing polarization- and phase-diversity detection on the filtered optical signal and converting it into multiple lane baseband electrical signals; analog-to-digital converters for sampling and quantizing the multiple lane baseband electrical signals so as to convert the them into multiple lane digital signals; a digital signal processing module for processing the multiple lane digital signals to obtain quality parameters; and an display module for displaying the quality parameters.

Abstract: The present invention discloses a method and an apparatus for measuring quality parameters of optical transmission channels. The apparatus comprises: a tunable optical filter for receiving an optical signal, performing wavelength or optical carrier demultiplexing on the optical signal, and out-of-band ASE noise suppression; an optical coherent receiver connected to the tunable optical filter, for performing polarization- and phase-diversity detection on the filtered optical signal and converting it into multiple lane baseband electrical signals; analog-to-digital converters for sampling and quantizing the multiple lane baseband electrical signals so as to convert the them into multiple lane digital signals; a digital signal processing module for processing the multiple lane digital signals to obtain quality parameters; and an display module for displaying the quality parameters.