大功率激光单模光纤远距离传输的注入光纤光功率限值分析

Analysis of Optical Power Limit of Injection Fiber for Long Distance Transmission of High Power Laser in Single Mode Fiber

对于大功率激光单模光纤远距离传输,采用传统的受激拉曼散射(SRS)阈值作为注入光纤激光功率值取值过大。本文对单模光纤远距离传输过程中泵浦光和拉曼斯托克斯光(Stokes)光功率随注入光纤激光功率的变化进行仿真与理论分析。根据光纤中SRS产生的机理,提出以拉曼Stokes光在单模光纤中传输的光功率变化曲线曲率极大值点对应的注入激光功率为限值,对注入单模光纤光功率限值随着光纤长度变化进行仿真,通过曲线拟合得出注入单模光纤激光功率限值公式,并搭建实验系统进行验证。结果表明,提出的注入单模光纤激光功率限值适用于大功率激光远距离单模光纤传输。

For long-distance transmission of high-power laser in single-mode fiber,traditional Raman scattering(SRS)threshold is used as the laser power of the injected fiber,which is too large.In this paper,the variation of pump and Stokes power with laser power of injected fiber of high-power laser over long-distance single-mode fiber is simulated and analyzed theoretically.According to the mechanism of SRS generation in the fiber,optical power limit of injected fiber suitable for high-power laser over long-distance single-mode fiber is proposed.The limit of injected laser power corresponds to the maximum curvature point of the power curve of Raman Stokes light propagating in a single-mode fiber.The variation of optical power limit with fiber length is simulated and a formula of laser power limit of single-mode fiber is obtained with curve fitting.Experimental results show that the formula is suitable for high-power laser over long-distance single-mode fiber.