设计了一种采用半导体可饱和吸收镜(SESAM)实现被动锁模的激光器,该激光器中只有单根的全固型掺镱光子带隙光纤(AS-Yb-PBGF)。在1 μm波段,该光纤具有负的群速度色散(GVD),因此腔内激光增益和负的GVD同时由该光纤提供。激光腔内非线性效应与仅由AS-Yb-PBGF提供的负GVD平衡作用可使激光器实现孤子运转。用分步傅里叶方法数值模拟了其孤子运转的动力学过程,该系统中初始的噪声信号经过数百次循环就可以得到稳定的孤子运转。输出脉冲能量为135 pJ,脉冲宽度为125 fs,时间带宽乘积为0.33,接近傅里叶变换极限的脉冲,脉冲重复频率可达500 MHz。系统地研究了整个激光器中孤子脉冲演变的动力学过程。

A passively mode-locked soliton laser is constructed employing semiconductor saturable absorber mirror (SESAM) as mode-locking regime. This laser only has single all-solid Yb-doped photonic bandgap fiber (AS-Yb-PBGF). At 1 μm wavelength region, the fiber has anomalous group velocity dispersion (GVD), thus it provides the laser gain and anomalous dispersion simultaneously. In the cavity, the balanced effect between the nonlinear effect and the anomalous GVD offered by the AS-Yb-PBGF can lead to soliton operation. By means of the split-step Fourier method, the dynamics of single-soliton operation in the laser is numerically simulated. At different initial signals the same stable soliton operation is finally obtained. The single-soliton operation with the pulse duration of 125 fs, the pulse energy up to 135 pJ has been shown, and the time-bandwidth product is 0.33 nearly the transform-limited pulse. The pulse repetition rate is up to 500 MHz. At the same time, the dynamics process of the pulse in the cavity is systemically studied.