Lin Yu-Chieh, Nabekawa Yasuo, Midorikawa Katsumi
Attosecond Science Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, No. 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Nat Commun. 2020 Jul 8;11(1):3413. doi: 10.1038/s41467-020-17247-9.
Few-cycle short-wave infrared (SWIR) pulses are useful tools for research on strong-field physics and nonlinear optics. Here we demonstrate the amplification of sub-cycle pulses in the SWIR region by using a cascaded BBO-based optical parametric amplifier (OPA) chain. By virtue of the tailored wavelength of the pump pulse of 708 nm, we successfully obtained a gain bandwidth of more than one octave for a BBO crystal. The division and synthesis of the spectral components of the pulse in a Mach-Zehnder-type interferometer set in front of the final amplifier enabled us to control the dispersion of each spectral component using an acousto-optic programmable dispersive filter inserted in each arm of the interferometer. As a result, we successfully generated 0.73-optical-cycle pulses at 1.8 μm with a pulse energy of 32 μJ.
少周期短波红外（SWIR）脉冲是研究强场物理和非线性光学的有用工具。在此，我们展示了通过使用基于BBO的级联光学参量放大器（OPA）链在SWIR区域对亚周期脉冲的放大。借助708 nm泵浦脉冲的定制波长，我们成功地为BBO晶体获得了超过一个倍频程的增益带宽。在最终放大器前面设置的马赫-曾德尔型干涉仪中对脉冲光谱成分的分割与合成，使我们能够使用插入干涉仪各臂中的声光可编程色散滤波器来控制每个光谱成分的色散。结果，我们成功地在1.8μm处产生了脉宽为0.73光学周期、脉冲能量为32μJ的脉冲。
