介绍了一种基于LMS(Least mean square)算法的自适应滤波技术,该技术适用于激光-电磁超声检测(EMAT)过程中的噪声抑制。选择6016铝板表面裂纹的超声检测信号作为信号处理对象,采用Matlab设计的LMS自适应数字滤波器并对信号进行处理,结...介绍了一种基于LMS(Least mean square)算法的自适应滤波技术,该技术适用于激光-电磁超声检测(EMAT)过程中的噪声抑制。选择6016铝板表面裂纹的超声检测信号作为信号处理对象,采用Matlab设计的LMS自适应数字滤波器并对信号进行处理,结果表明该技术能够有效提高检测信号的可识别性,在激光-电磁超声工程应用领域中具有良好的应用前景。展开更多
Mode-locked lasing operations at 1064 and 910 nm wavelengths are demonstrated,respectively,in two all-fiber laser oscillators using our homemade Nd^(3+)-doped silica fiber(NDF)as the gain medium.The Al3+/Nd^(3+)co-dop...Mode-locked lasing operations at 1064 and 910 nm wavelengths are demonstrated,respectively,in two all-fiber laser oscillators using our homemade Nd^(3+)-doped silica fiber(NDF)as the gain medium.The Al3+/Nd^(3+)co-doped silica core glass was fabricated by the modified sol-gel method with 18,300×10^(-6) Nd^(3+)doping concentration.The NDF drawn by the rodin-tube method has a core of 4μm in diameter and a numerical aperture(NA)of 0.14.At 1064 nm,we measure an average laser output power of 18mWwith a pulse duration of 5.75 ps,a pulse energy of 1.14 nJ,and a slope efficiency of 7.2%.Using the same NDF gain fiber of a different length,a maximum average laser output power is 3.1 mW at 910 nm with a pulse duration of 877 ns,a pulse energy of 2.7 nJ,and a slope efficiency of 1.44%.展开更多
文摘介绍了一种基于LMS(Least mean square)算法的自适应滤波技术,该技术适用于激光-电磁超声检测(EMAT)过程中的噪声抑制。选择6016铝板表面裂纹的超声检测信号作为信号处理对象,采用Matlab设计的LMS自适应数字滤波器并对信号进行处理,结果表明该技术能够有效提高检测信号的可识别性,在激光-电磁超声工程应用领域中具有良好的应用前景。
基金supported by the Key Technology Research and Development Program of Shandong Province(No.2021CXGC010202)Chinese Academy of Sciences(No.ZDBS-LY-JSC020)+1 种基金the National Key Research and Development Program of China(No.2020YFB1312802)the National Natural Science Foundation of China(Nos.61935002,62205356,and 61975216).
文摘Mode-locked lasing operations at 1064 and 910 nm wavelengths are demonstrated,respectively,in two all-fiber laser oscillators using our homemade Nd^(3+)-doped silica fiber(NDF)as the gain medium.The Al3+/Nd^(3+)co-doped silica core glass was fabricated by the modified sol-gel method with 18,300×10^(-6) Nd^(3+)doping concentration.The NDF drawn by the rodin-tube method has a core of 4μm in diameter and a numerical aperture(NA)of 0.14.At 1064 nm,we measure an average laser output power of 18mWwith a pulse duration of 5.75 ps,a pulse energy of 1.14 nJ,and a slope efficiency of 7.2%.Using the same NDF gain fiber of a different length,a maximum average laser output power is 3.1 mW at 910 nm with a pulse duration of 877 ns,a pulse energy of 2.7 nJ,and a slope efficiency of 1.44%.
