High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission ph...High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission phase and identifying the HHG mechanism.However,achieving this feature by applying traditional two-beam far-field interferometry to solid materials remains challenging.In this study,we present a novel interferometric approach that utilizes a single laser beam to excite two ZnO microwires(MWs)simultaneously,thereby generating coherent high-harmonic sources that form interference fringes in the far-field region.We leverage the diameter-dependent field-enhancement effect in MWs to measure the intensity-dependent fringe shift,revealing that the intraband current mechanism dominates the below-bandgap harmonic,whereas the interband polarization mechanism dominates the above-bandgap harmonic.This study offers a robust method for measuring the dipole phase of solid-state HHG and inspires intensity-modulated high-harmonic applications in coherent imaging and microdevice design.展开更多
基金supported by the National Key R&D Program of China (Grant Nos.2023YFA1406801 and 2022YFA1604301)the National Natural Science Foundation of China (Grant Nos.12434013,12595343,12404393,and 12174011)。
文摘High harmonic generation(HHG)provides an experimental method for producing attosecond pulses and probing electron dynamics.Achieving precise dipole phase measurements is critical for tailoring the harmonic emission phase and identifying the HHG mechanism.However,achieving this feature by applying traditional two-beam far-field interferometry to solid materials remains challenging.In this study,we present a novel interferometric approach that utilizes a single laser beam to excite two ZnO microwires(MWs)simultaneously,thereby generating coherent high-harmonic sources that form interference fringes in the far-field region.We leverage the diameter-dependent field-enhancement effect in MWs to measure the intensity-dependent fringe shift,revealing that the intraband current mechanism dominates the below-bandgap harmonic,whereas the interband polarization mechanism dominates the above-bandgap harmonic.This study offers a robust method for measuring the dipole phase of solid-state HHG and inspires intensity-modulated high-harmonic applications in coherent imaging and microdevice design.
文摘【目的】早发性肌无力综合征(early onset muscle weakness syndrome,MW)是新近发现的一种荷斯坦牛遗传缺陷,患病犊牛表现为出生后趴卧不起、后肢肌肉萎缩等,其遗传机制与L型钙通道蛋白α1S亚基编码基因CACNA1S的单碱基突变相关。本研究旨在建立该遗传缺陷的分子检测方法,并探究其在国内荷斯坦牛群体中的扩散情况。【方法】基于MW致病位点特异性DNA序列,设计扩增阻滞突变系统-聚合酶链式反应(ARMS-PCR)检测引物,对317份荷斯坦牛冻精和毛囊样本进行MW遗传缺陷基因筛查,通过Sanger测序对ARMS-PCR检测结果进行验证,并利用系谱数据追溯MW突变源头。【结果】ARMS-PCR检出MW携带者21头,携带率为6.62%(21/317),未发现缺陷基因纯合子,提示该突变为隐性纯合致死。Sanger测序与ARMS-PCR所得基因型完全一致,证明该技术具有高度准确性。系谱追溯表明,MW携带者的遗传来源可追溯至1984年出生的荷斯坦公牛Southwind Bell of Bar-Lee。【结论】MW遗传缺陷已在中国荷斯坦牛群体中扩散且携带率较高,建议牧场应尽早开展MW遗传缺陷基因检测和风险评估,采取科学的选种选配措施以减少遗传缺陷导致的经济损失。
