基于全固型掺镱光子带隙光纤的被动锁模全光纤环形孤子激光器

Passively Mode-Locked All-Fiber Ring Soliton Laser Based on All-Solid Yb-Doped Photonic Bandgap Fiber

采用全固型掺镱光子带隙光纤(AS-Yb-PBGF)作增益介质并提供反常群速色散(GVD),设计了一种被动锁模全光纤环形孤子激光器。没有使用任何块状色散补偿元件。因此,该激光器腔型结构简单、紧凑、环境稳定性高,更容易实现全光纤结构。脉冲在激光腔内的传输用广义非线性薛定谔方程描述,并采用分步傅里叶方法数值模拟了该激光器的单孤子运转的动力学过程。计算时,将AS-Yb-PBGF的长度选取为0.4m,改变激光腔内单模光纤(SMF)的长度,得出了最佳运转参数:当AS-Yb-PBGF固定为0.4 m时,选择单模光纤等于0.4 m,就可以实现脉冲宽度为244 fs,脉冲能量为14 pJ和时间带宽乘积为0.32,即接近傅里叶变换极限的单孤子运转。

A passively mode-locked all-fiber ring soliton laser is constructed based on all-solid Yb-doped photonic bandgap fibers （AS-Yb-PBGF）, which provide the laser gain and anomalous dispersion simultaneously. Without using any bulk dispersion compensators, the laser cavity is simple, compact, environmentally stable, and easy to achieve all-fiber configuration. By means of the nonlinear Schrodinger equation, the dynamics of single-soliton operation in the laser is numerically simulated and the optimal parameter is obtained with the split-step Fourier method. In the calculation, when the length of the AS-Yb-PBGF was chosen as 0.4 m and the length of single mode fiber （SMF） as 0.4 m, the single-soliton operation with the pulse duration of 244 fs, the pulse energy up to 14 pJ, in which the time-bandwidth product is 0.32 as nearly the transform-limited pulse, has been shown.