Szatmári Sándor, Nagy Tamás, Dajka Rita, Kedves Miklós Á, Aladi Márk, Földes István B
Opt Express. 2024 May 6;32(10):17038-17047. doi: 10.1364/OE.521567.
Temporal cleaning of high-power infrared (IR) pulses generated by a Ti:Sapphire system is demonstrated by the use of the Nonlinear Fourier Filtering (NFF) method. In a proof-of-principle experiment suppression of up to 1000 is achieved for the temporal pedestal prior to the main pulse, with a moderate (20-25%) overall throughput. This includes the same suppression ratio for the picosecond coherent pedestal in the direct vicinity of the main pulse. Based on the instantaneous, intensity-dependent and high-order switching characteristics of NFF, excellent pulse cleaning performance is observed. The efficient, high-contrast removal of the coherent pedestal from the foot of the main pulse even if its duration is shorter than 100 fs is compared with the capability of the plasma mirror technique. Calculations are also performed, supporting the experimentally observed sharp intensity dependence of the switching process, pointing out the dominant role of the ionization-based refractive index change.
通过使用非线性傅里叶滤波（NFF）方法，展示了对钛宝石系统产生的高功率红外（IR）脉冲进行时间清理的过程。在原理验证实验中，主脉冲之前的时间基座抑制高达1000倍，整体通量适中（20 - 25%）。这包括主脉冲紧邻区域皮秒相干基座的相同抑制比。基于NFF的瞬时、强度依赖和高阶开关特性，观察到了出色的脉冲清理性能。将即使主脉冲前沿相干基座持续时间短于100 fs时，从主脉冲前沿高效、高对比度地去除相干基座的能力与等离子体镜技术的能力进行了比较。还进行了计算，支持了实验观察到的开关过程对强度的强烈依赖性，指出了基于电离的折射率变化的主导作用。
