Boltaev Ganjaboy S, Ganeev Rashid A, Kim Vyacheslav V, Abbasi Naveed A, Iqbal Mazhar, Alnaser Ali S
Opt Express. 2020 Jun 22;28(13):18859-18875. doi: 10.1364/OE.393054.
We analyze the high-order harmonics generation using 1 kHz and 100 kHz lasers by ablating different rotating targets. We demonstrate the high average flux of short-wavelength radiation using the latter laser, while comparing the plasma formation conditions at different pulse repetition rates. The analysis of harmonic stability in the case of the 100 kHz experiments showed the two-fold decay of the 27 harmonic generating in silver plasma after 3.5×10 shots. The advantages of shorter pulse-induced ablation for the improvement of harmonic generation stability are demonstrated. Two-color pump of plasma, resonance enhancement of single harmonic, and quasi-phase matching studies are presented for 1 kHz laser applications. The formation of modulated multi-jet plasma on the plane and curved surfaces during ablation by 100 kHz pulses is demonstrated. In the case of the 25 harmonic of 1030 nm radiation (E=30 eV) generated during experiments in carbon plasma, at 100 kHz and 40 W average power of driving pulses, 0.4 mW of average power for single harmonic in the 40 nm spectral range was achieved.
我们通过烧蚀不同的旋转靶材，利用1kHz和100kHz的激光分析高次谐波的产生。在比较不同脉冲重复率下的等离子体形成条件时，我们利用后一种激光展示了短波长辐射的高平均通量。对100kHz实验中谐波稳定性的分析表明，在银等离子体中产生的27次谐波在3.5×10次脉冲后衰减了两倍。展示了较短脉冲诱导烧蚀在提高谐波产生稳定性方面的优势。针对1kHz激光应用，介绍了等离子体的双色泵浦、单谐波的共振增强以及准相位匹配研究。展示了在100kHz脉冲烧蚀过程中，平面和曲面上调制多喷流等离子体的形成。在碳等离子体实验中，当驱动脉冲的平均功率为100kHz和40W时，在1030 nm辐射（E=30 eV）的25次谐波情况下，在40 nm光谱范围内实现了单谐波0.4 mW的平均功率。
