Hwang Sung In, Park Seung Beom, Mun Jehoi, Cho Wosik, Nam Chang Hee, Kim Kyung Taec
Center for Relativistic Laser Science, Institute for Basic Science, Gwangju, 61005, Korea.
Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
Sci Rep. 2019 Feb 7;9(1):1613. doi: 10.1038/s41598-018-38220-z.
A single-cycle laser pulse was generated using a two-stage compressor and characterized using a pulse characterization technique based on tunnelling ionization. A 25-fs, 800-nm laser pulse was compressed to 5.5 fs using a gas-filled hollow-core fibre and a set of chirped mirrors. The laser pulse was further compressed, down to the single-cycle limit by propagation through multiple fused-silica plates and another set of chirped mirrors. The two-stage compressor mitigates the development of higher-order dispersion during spectral broadening. Thus, a single-cycle pulse was generated by compensating the second-order dispersion using chirped mirrors. The duration of the single-cycle pulse was 2.5 fs, while its transform-limited duration was 2.2 fs. A continuum extreme ultraviolet spectrum was obtained through high-harmonic generation without applying any temporal gating technique. The continuum spectrum was shown to have a strong dependence on the carrier-envelope phase of the laser pulse, confirming the generation of a single-cycle pulse.
使用两级压缩器产生单周期激光脉冲，并采用基于隧穿电离的脉冲表征技术对其进行表征。一个25飞秒、800纳米的激光脉冲通过充气空心光纤和一组啁啾镜被压缩至5.5飞秒。通过多个熔融石英板和另一组啁啾镜的传播，激光脉冲进一步被压缩至单周期极限。两级压缩器减轻了光谱展宽过程中高阶色散的产生。因此，通过使用啁啾镜补偿二阶色散产生了单周期脉冲。单周期脉冲的持续时间为2.5飞秒，而其变换极限持续时间为2.2飞秒。在未应用任何时间选通技术的情况下，通过高次谐波产生获得了连续极端紫外光谱。该连续光谱显示出对激光脉冲载波包络相位有强烈依赖性，证实了单周期脉冲的产生。
