掺Yb/掺Er双色矢量孤子光纤激光及其动力学特性研究

双色锁模光纤激光器在光纤通信、拉曼散射光谱学、差频混合等领域具有重要应用价值。目前，对于双色锁模光纤激光器的研究大都是在标量近似下进行的，关于其矢量特性研究的报道很少。针对上述问题，本项目首先利用掺Yb和掺Er光纤作为增益介质，偏振不敏感纳米材料作为饱和吸收体，搭建全光纤双色被动锁模环形谐振腔；然后，结合理论模拟，通过改变腔内实验参数，实现1.06／1.55-μm双色矢量孤子光纤激光输出，确立不同种类双色矢量孤子的稳定存在区域和相互转换条件，并采用时间拉伸色散傅里叶变换技术研究双色矢量孤子及其正交偏振分量的瞬态动力学特性；最后，通过改变双色激光的时间延迟，结合泵浦功率和线性双折射的变化，研究交叉相位调制对双色矢量孤子光纤激光输出特性的作用规律。本项目进一步探索非线性光学系统中双色矢量孤子的动力学特性，为其它波段的双色以及多色矢量孤子光纤激光器的研究提供铺垫。

Two-color mode-locked fiber laser has important applications in the fields of optical fiber communication, Raman scattering spectroscopy, differential frequency mixing and so on. At present, most research about two-color mode-locked fiber laser is under the condition of scalar approximation. There are few reports about the vector property of two-color mode-locked fiber laser. In this project, firstly, Yb- and Er-doped gain fibers are used as gain media, accompanied with polarization insensitive nanomaterial-based saturable absorber, to construct an all fiber two-color passively mode-locked ring resonator. Then, combined with theoretical simulation, 1.06/1.55-μm two-color vector soliton fiber laser is achieved by adjusting intra-cavity experimental parameters. The stable existing regions and mutual conversion conditions of different kinds of vector solitons are established. The transient dynamic properties of two-color vector soliton and its orthogonal polarization modes are studied by using time-stretch dispersion Fourier transformation technique. Finally, through changing time delay of two-color laser, combining with the change of pump power and linear birefringence, we study the function of cross-phase modulation on the output characteristics of two-color vector soliton fiber laser. This project further explores the dynamic characteristics of two-color vector soliton in nonlinear optical system, and provides beneficial conduct for future research on two-color at other wavelength bands and multi-color vector soliton fiber lasers.