Tang Daolong, Ma Jingui, Wang Jing, Zhou Bingjie, Xie Guoqiang, Yuan Peng, Zhu Heyuan, Qian Liejia
Key Laboratory for Laser Plasma (Ministry of Education), Department of Physics and Astronomy, Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China.
Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China.
Sci Rep. 2016 Oct 27;6:36059. doi: 10.1038/srep36059.
Optical parametric chirped-pulse amplification (OPCPA) has been demonstrated to be a promising approach for pushing femtosecond pulses towards ultra-high peak powers. However, the future success of OPCPA strongly relies on the ability to manipulate its phase-matching (PM) configuration. When a high average power pump laser is involved, the thermal effects in nonlinear crystals induce phase-mismatch distortions that pose an inherent limitation on the conversion efficiency. Here, we demonstrate that the noncollinear configuration previously adopted for wavelength-insensitive PM can be employed for temperature-insensitive PM when the noncollinear angle is properly reset. Simultaneous temperature- and wavelength-insensitive PM is realized for the first time by imposing such a temperature-insensitive noncollinear configuration with an angularly dispersed seed signal. Based on the lithium triborate crystal, the proposed noncollinear achromatic PM has a thermal acceptance 6 times larger than that of the conventional wavelength-insensitive noncollinear PM and has a sufficient spectral acceptance to support pulse durations of ~20 fs at 800 nm. These achievements open new possibilities for generating ultra-high peak power lasers with high average power.
光学参量啁啾脉冲放大（OPCPA）已被证明是一种将飞秒脉冲推向超高峰值功率的有前途的方法。然而，OPCPA未来的成功强烈依赖于操纵其相位匹配（PM）配置的能力。当涉及高平均功率泵浦激光器时，非线性晶体中的热效应会引起相位失配畸变，这对转换效率构成了固有的限制。在此，我们证明，当非共线角适当地重新设置时，先前用于波长不敏感PM的非共线配置可用于温度不敏感PM。通过将这种温度不敏感的非共线配置与角度色散种子信号相结合，首次实现了同时对温度和波长不敏感的PM。基于硼酸三锂晶体，所提出的非共线消色差PM的热接受度比传统的波长不敏感非共线PM大6倍，并且具有足够的光谱接受度，以支持800nm处约20 fs的脉冲持续时间。这些成果为产生具有高平均功率的超高峰值功率激光器开辟了新的可能性。
