Ultrashort visible-near infrared (NIR) pulse generation and its applications to ultrafast spectroscopy are discussed. Femtosecond pulses of around 800 nm from a Ti:sapphire laser are used as a pump of an optical parametric amplifier (OPA) in a non-collinear configuration to generate ultrashort visible (500–780 nm) pulses and deep-ultraviolet (DUV, 259–282 nm) pulses. The visible-NIR pulses and DUV pulses were compressed to 3.9 fs and 10.4 fs, respectively, and used to elucidate various ultrafast dynamics in condensed matter with a sub-10 fs resolution by pump-probe measurements. We have also developed a 128-channel lock-in amplifier. The combined system of the world-shortest visible pulse from the OPA and the lock-in amplifier with the world-largest channel-number can clarify the sub-10 fs-dynamics in condensed matter. This system clarified structural changes in an excited state, reaction intermediate, and a transition state. This is possible even during molecular vibration and reactions via a real-time-resolved vibronic spectrum, which provides molecular structural change information. Also, ultrafast dynamics in exotic materials like carbon nanotubes, topological insulators, and novel solar battery systems have been clarified. Furthermore, the carrier-envelope phase in the ultrashort pulse has been controlled and measured.

讨论了超短可见-近红外 (NIR) 脉冲的产生及其在超快光谱中的应用。来自钛蓝宝石激光器的约 800 nm 飞秒脉冲被用作非共线配置的光学参量放大器 (OPA) 的泵浦，以产生超短可见光 (500–780 nm) 脉冲和深紫外 (DUV, 259 –282 nm) 脉冲。可见光 NIR 脉冲和 DUV 脉冲分别被压缩到 3.9 fs 和 10.4 fs，并用于通过泵探针测量阐明具有亚 10 fs 分辨率的凝聚态物质中的各种超快动力学。我们还开发了 128 通道锁定放大器。来自OPA的世界最短可见脉冲和世界最大通道数的锁定放大器的组合系统可以阐明凝聚态物质中的亚10 fs动力学。该系统阐明了激发态、反应中间体和过渡态的结构变化。即使在分子振动和反应过程中，这也是可能的通过实时分辨的振动光谱，提供分子结构变化信息。此外，碳纳米管、拓扑绝缘体和新型太阳能电池系统等奇异材料的超快动力学也得到了阐明。此外，超短脉冲中的载波包络相位已得到控制和测量。