基于啁啾FBG的三角形光脉冲发生器的优化设计

提出了利用啁啾光纤布拉格光栅(FBG)和马赫增德尔调制器产生三角形光脉冲的优化方案.方案采用FBG模拟单模光纤的色散特性,结合光载波抑制调制产生了三角形光脉冲, 并通过仿真分析,选择FBG的长度、调制深度、适当的折射率切趾函数对三角形光脉冲的线性特征进行了优化.仿真结果表明,在同一啁啾系数下,产生的三角形光脉冲的失真程度随啁啾光纤光栅的调制深度增大而增大,光栅长度、折射率切趾函数对三角形光脉冲的影响也比较明显.与现有系统相比,由于将FBG引入系统,省去长距离的光纤,优化方案系统结构更为简单,三角形光脉冲线性特征更好.

Optimization of optical triangular pulses generator based on chirped fiber Bragg grating

An optimized scheme was proposed to generate optical triangular pulses by using chirped fiber Bragg grating(FBG) and Mach-Zehnder modulator. Optical triangular pulses were obtained based on dispersion character of standard single-mode fiber substituted for a chirped FBG combined with optical carrier suppression modulation. The obtained triangular pulses' linear feature was optimized by simulation analysis of length, modulation index, and appropriate apodization of FBG. The simulation results indicate that the distortion of finally generated triangular pulses increase with the modulation index's raising under the same chirp coefficient. The length of fiber grating and the apodization also have an obvious impact on the triangular pulses. Compared with the present generator, the proposed system has distinct advantages of simple configuration and the triangular pulses have better linear characteristic own to the small size chirped fiber grating replacing the long distance optical fiber.