THz pulses are generated from femtosecond pulse-excited ferromagnetic/nonmagnetic spintronic heterostructures via inverse spin Hall effect. The highest possible THz signal strength from spintronic THz emitters is limited by the optical damage threshold of the corresponding heterostructures at the excitation wavelength. For the thickness-optimized spintronic heterostructure, the THz generation efficiency does not saturate with the excitation fluence even up till the damage threshold. Bilayer (Fe, CoFeB)/(Pt, Ta)-based ferromagnetic/nonmagnetic (FM/NM) spintronic heterostructures have been studied for an optimized performance for THz generation when pumped by sub-50 fs amplified laser pulses at 800 nm. Among them, CoFeB/Pt is the best combination for an efficient THz source. The optimized FM/NM spintronic heterostructure having α-phase Ta as the nonmagnetic layer shows the highest damage threshold as compared to those with Pt, irrespective of their generation efficiency. The damage threshold of the Fe/Ta heterostructure on a quartz substrate is ∼85 GW/cm².

太赫兹脉冲是通过反自旋霍尔效应从飞秒脉冲激发的铁磁/非磁性自旋电子异质结构产生的。自旋电子太赫兹发射器的最高可能太赫兹信号强度受到激发波长下相应异质结构的光学损伤阈值的限制。对于厚度优化的自旋电子异质结构，即使在损伤阈值之前，THz 生成效率也不会随着激发注量而饱和。已经研究了基于双层 (Fe, CoFeB)/(Pt, Ta) 的铁磁性/非磁性 (FM/NM) 自旋电子异质结构，以优化当由 800 nm 的亚 50 fs 放大激光脉冲泵浦时产生太赫兹的性能。其中，CoFeB/Pt 是高效太赫兹源的最佳组合。与具有 Pt 的那些相比，具有 α 相 Ta 作为非磁性层的优化的 FM/NM 自旋电子异质结构显示出最高的损伤阈值，无论它们的生成效率如何。Fe/Ta异质结在石英衬底上的损伤阈值为~85 GW/cm² .