介绍了非线性光纤环镜的基本原理,以及利用光束传输法对耦合非线性薛定谔方程组进行数值分析,研究并搭建了采用非线性光纤环境作为介质,实现波长变换的实验系统,经实验证明,非线性光纤环路境能够将2.5 G bit/s归零码光脉冲波长变换20 nm...介绍了非线性光纤环镜的基本原理,以及利用光束传输法对耦合非线性薛定谔方程组进行数值分析,研究并搭建了采用非线性光纤环境作为介质,实现波长变换的实验系统,经实验证明,非线性光纤环路境能够将2.5 G bit/s归零码光脉冲波长变换20 nm,也能同时实现两个波长的转换。展开更多
The interaction of continuous wave （CW） fiber laser with Ti-6A1-4V alloy is investigated numerically and experi- mentally at different laser fluence values and ambient pressures of N2 atmosphere to determine the mel...The interaction of continuous wave （CW） fiber laser with Ti-6A1-4V alloy is investigated numerically and experi- mentally at different laser fluence values and ambient pressures of N2 atmosphere to determine the melting time threshold of Ti-6A1-4V alloy.＇ A 2D-axisymmetric numerical model considering heat transfer and laminar flow is es- tablished to describe the melting process. The simulation results indicate that material melts earlier at lower pressure （8.0 Pa） than at higher pressure （8.8x 104 Pa） in several milliseconds with the same laser fluence. The experimental results demonstrate that the melting time threshold at high laser fluence （above 1.89x 108 W/m2） is shorter for lower pressure （vacuum）, which is consistent with the simulation. While the melting time threshold at low laser fluence （below 1.89x 108 W/m2） is shorter for higher pressure. The possible aspects which can affect the melting process in- clude the increased heat loss induced by the heat conduction between the metal surface and the ambient gas with the increased pressure, and the absorption variation of the coarse surface resulted from the chemical reaction.展开更多
基金supported by the National Natural Science Foundation of China for Young Scholars(No.11402120)the Jiangsu Provincial Natural Science Foundation for Young Scholars(No.BK20140796)the Fundamental Research Funds for the Central Universities(No.30915015104)
文摘The interaction of continuous wave （CW） fiber laser with Ti-6A1-4V alloy is investigated numerically and experi- mentally at different laser fluence values and ambient pressures of N2 atmosphere to determine the melting time threshold of Ti-6A1-4V alloy.＇ A 2D-axisymmetric numerical model considering heat transfer and laminar flow is es- tablished to describe the melting process. The simulation results indicate that material melts earlier at lower pressure （8.0 Pa） than at higher pressure （8.8x 104 Pa） in several milliseconds with the same laser fluence. The experimental results demonstrate that the melting time threshold at high laser fluence （above 1.89x 108 W/m2） is shorter for lower pressure （vacuum）, which is consistent with the simulation. While the melting time threshold at low laser fluence （below 1.89x 108 W/m2） is shorter for higher pressure. The possible aspects which can affect the melting process in- clude the increased heat loss induced by the heat conduction between the metal surface and the ambient gas with the increased pressure, and the absorption variation of the coarse surface resulted from the chemical reaction.
