高稳定性1.3微米亚纳秒级脉冲激光特性研究

Due to the advantages of high peak power and stability, all-solid-state sub-nanosecond lasers at 1.3μm have wide applications in information storage, non-linear optics and medical treatment. It is difficult to obtain high peak power and high stability sub nanosecond laser pulse by using single-loss modulated Q-switching, Q-switching and mode-locking (QML) or continuous mode-locking technique. Dual-loss-modulated QML lasers involve two dynamical processes of Q-switching and mode-locking, from which the single mode-locked pulse underneath the Q-switched envelope with sub nanosecond duration can be generated. The repetition frequency of the pulse is controlled by the active modulator, which enhances the stability of the laser pulse and increases the peak power of the pulse. This project realizes stable sub-nanosecond lasers at 1.3μm by using both proper active modulator and passive saturable absorber (SESAM/SWCNT-SA/Graphene) and researches microscopic mechanism of single mode-locking pulse laser at 1.3μm. There is only one mode-locked pulse with sub-nanosecond duration in a Q-switched envelope. The results obtained in this work are expected to provide theoretical and experimental supports for realizing optimal design of 1.3μm pulse laser. Meanwhile the investigation can contribute to expand the application of 1.3μm sub-nanosecond pulse laser.

全固态、高峰值功率、高稳定性、亚纳秒级1.3μm激光在信息存储、非线性光学、医学治疗等领域具有广阔的应用。利用单一损耗调制的调Q、调Q锁模或连续锁模技术，均难以获得高峰值功率、高稳定性的亚纳秒级短脉冲激光。主被动双调Q锁模激光器可实现调Q包络内单一锁模脉冲输出，锁模脉宽为亚纳秒级，其脉冲的重复频率与主动调制频率相同，增强了激光脉冲稳定性，提高了脉冲峰值功率。本项目拟将主动（声光、电光）调制与饱和吸收体被动调制相结合，在谐振腔内同时使用两种损耗调制，实现1.3μm波段亚纳秒级激光脉冲（调Q包络内单一锁模脉冲）的稳定输出，探索1.3μm双调Q锁模激光器脉宽压缩机理，研究影响单一锁模脉冲输出稳定性的相关因素，揭示利用双损耗调制产生1.3μm稳定亚纳秒激光脉冲的原理，为1.3μm脉冲激光器件的进一步优化设计提供规律性依据，展现单一锁模脉冲输出的1.3μm脉冲激光在固体激光器件方面的应用前景。

1.3微米亚纳秒激光脉冲在非线性光学、荧光激发、激光检测等领域具有良好的应用前景。本项目利用电光主动调制器与二维材料可饱和吸收体，从理论和实验两个方面探究了1.3微米亚纳秒激光脉冲输出。首先，综合考虑主动调制器件与被动可饱和吸收体的影响，完成了1.3微米双调Q锁模激光器输出参数优化；其次，以电光调制器与V3+:YAG作为主被动调制器件，建立了描述1.3微米亚纳秒激光脉冲输出的速率方程组，并实现了稳定输出的亚纳秒脉冲参数的数值模拟；再次，利用液相剥离法制备出成本较低，光学性质良好的氧化石墨烯及二硫化钼可饱和吸收体，分别使用调Q技术和调Q锁模技术两种手段，先后实现了1.06微米及1.3微米两个波段的激光脉冲输出，揭示了二维材料可饱和吸收体在1.3微米全固态激光器中的应用前景；最后，将主动调制器件加入激光器，探究了双损耗调制对脉冲的影响，总结了1.3微米波段调Q锁模激光器输出亚纳秒量级激光脉冲的运转规律，为1.3微米脉冲激光器件的进一步优化设计提供方法与思路。