基于级联光纤的全光纤中红外宽带可调谐孤子光源研究

Mid-infrared (MIR) ultrafast laser has important applications in many fields, such as basic science, medicine, and military. At present, the optical parametric oscillator laser (OPO) is mainly used to achieve tunable laser output in MIR band. Compared to fiber laser, the OPO system is complex..This project will use cascaded tellurite and fluoride fibers to obtain 2-5 μm wideband tunable all-fiber MIR ultrafast laser. We will take use of the soliton self-frequency shift (SSFS) effect in nonlinear fiber. Firstly, we will pump tellurite fiber by 2 μm ultrafast fiber laser to generate soliton with maximum wavelength of 3 μm. Then, the obtained soliton source with wavelength of 3 μm will be used to pump fluoride fiber. Soliton with maximum wavelength of 5 μm will be generated in the fluoride fiber. Finally, an all-fiber MIR ultrafast soliton source with wavelength tunable from 2 to 5 μm will be obtained..We will study high conversion efficiency, wideband tunable SSFS effect theoretically and deeply. We will solve the problem of fiber design and fiber drawing of cascaded tellurite and fluoride fibers, which is suitable for SSFS. To increase the amount of soliton frequency shift, we will precisely control fiber dispersion through tapering fiber. In order to make an all-fiber device, we will solve the problem of low loss connection of different kinds of optical fibers. This project will play a positive role in the development of new type miniaturized and integrated MIR ultrafast light.

中红外超快激光在基础科学、医学、军事等众多领域都具有重要的应用价值。目前主要是用光参量振荡激光器实现中红外可调谐超快激光输出，与光纤激光器相比，系统复杂。.本项目将利用级联的碲酸盐、氟化物光纤获得波长2-5微米宽带可调谐的全光纤中红外超快激光。我们将利用光纤中的孤子自频移效应，先用2微米的超快光纤激光泵浦碲酸盐光纤产生最大波长3微米附近的孤子，然后用得到的3微米孤子光源泵浦氟化物光纤，在氟化物光纤中产生最大波长5微米附近的孤子，最终在级联的碲酸盐、氟化物光纤中获得目标波段的超快孤子光源。.我们将深入进行高转换效率、宽带可调谐孤子自频移的理论研究，解决适用于孤子自频移的级联碲酸盐、氟化物光纤的设计和制备问题，通过拉锥光纤精密调控光纤色散，增加孤子频移量。我们将解决不同种光纤的低损耗熔接问题，使整个装置全光纤化。项目的开展将对开发小型化、集成化的新型中红外超快光源起到积极的推动作用。

中红外超快激光在基础科学、医学、军事等众多领域都具有重要的应用价值。本研究拟利用级联的碲酸盐、氟化物光纤获得宽带可调谐的全光纤中红外超快激光。利用光纤中的孤子自频移效应，先用2微米的超快光纤激光泵浦碲酸盐光纤产生最大波长3微米附近的孤子，然后用得到的3微米孤子光源泵浦氟化物光纤，在级联的碲酸盐、氟化物光纤中获得目标波段的超快孤子光源。项目基本达到了研究目标。进行了孤子自频移的理论研究，设计并制备了碲酸盐、氟化物光纤，研究了非石英基光纤的熔接，研究了不同泵浦条件下非线性光纤中的超连续谱产生过程，获得了中红外波段的超连续谱输出。