拓扑绝缘体与模间拍频锁模新机制用于中红外超快光纤拉曼激光器的研究

项目名称： 拓扑绝缘体与模间拍频锁模新机制用于中红外超快光纤拉曼激光器的研究

项目编号： No.61475129

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 罗正钱

作者单位： 厦门大学

项目金额： 82万元

中文摘要： 2-5μm中红外超短脉冲激光源在医疗、军事、通信及环境监测等领域具有重要应用。本项目以发展小型化、高性能中红外超短脉冲激光器为动机，针对传统锁模技术大多难以适用于中红外波段的问题，开发新型锁模技术- - 拓扑绝缘体和模间拍频锁模在中红外波段的巨大潜力，结合氟化物/硫化物光纤产生中红外拉曼增益的优势，研究实现中红外锁模超短脉冲光纤激光器。主要研究内容包括：1）阐明模间拍频锁模的动力学运行机制，探索拉曼泵浦源、谐振腔参数等对模间拍频锁模运转的影响，弄清其锁模脉冲、光谱及频谱的特征；2）利用化学液相剥离法和MBE法，研制中红外拓扑绝缘体锁模器件；3）开展拓扑绝缘体/模间拍频锁模中红外拉曼光纤激光器的理论分析和实验研究，以期实现中心波长在2.2-3.3μm可调谐、 重复率可达10GHz、脉宽<500fs的高功率锁模脉冲。本项目的研究将不仅对锁模机理产生新认识，而且为研制小型化中红外锁模激光器提供新思路

中文关键词： 锁模光纤激光器；中红外；非线性光纤光学；拓扑绝缘体；模间拍频锁模

英文摘要： Ultrashort pulsed laser sources in 2-5 μm mid-infrared (MIR) region have opened some important applications in fields such as medicine, military, free-space communications and environmental monitoring. However, because the current MIR ultrashort pulsed lasers are mostly obtained by free-electron lasers or nonlinear parametric/difference-frequency generation in crystal lasers, they are usually complex, bulky and extremely expensive. Therefore, more-compact, user-friendly and economical MIR ultrashort pulsed lasers are urgently expected in some applications. An ideal solution is to mode lock fiber lasers in MIR region, but the key problem is that most of conventional mode-locking techniques cannot well work in MIR region. In this project, to solve this problem, we propose two novel mode-locking techniques, i.e. intermode-beating mode-locking (IBML) & topological-insulator saturable absorbers, which are potential for mode-locking in MIR region. By further combining a fluoride or chalcogenide fiber as MIR Raman gain medium, we will try to explore compact and high-performance MIR ultrashort pulsed fiber laser. The research contents mainly contain: 1)theoretically clarifying the dynamic mechanism of the proposed IBML, investigating the effects of Raman pump source, Raman-resonant-cavity's parameters on the IBML operation, and clearly understanding the features of the IBML mode-locked pulses, optical and radio-frequency spectra; 2) by the liquid-phase exfoliation method and the MBE technique, fabricating the high-perfomance topological insulators as MIR mode-lockers and further investigating their saturable-absroption properties in MIR region; 3)based on the two mode-locking techniques in above, performing the theoretical analysis, numerical simulations and experimental research to realize the optimal output of MIR mode-locked fiber Raman lasers. The research of this project will not only help us to deeply understand the new mode-locking mechanisms, but also may open a new way for developing compact, high-performance MIR mode-locked fiber lasers.

英文关键词： mode-locked fiber lasers;mid-infrared;nonlinear fiber optics;topological insulator;intermodal-beating mode-locking