利用低频场控制轨道直接产生低于50阿秒的单个脉冲  

Direct generation of isolated sub-50 attosecond pulse via controlling quantum paths by a low frequency field

作　　者：洪伟毅[1] 杨振宇[1] 兰鹏飞[1] 陆培祥[1] 

机构地区：[1]武汉光电国家实验室,华中科技大学,武汉430074

出　　处：《物理学报》2008年第9期5853-5858,共6页Acta Physica Sinica

基　　金：教育部博士点基金(批准号:20040487023);国家自然科学基金(批准号:10574050)资助的课题~~

摘　　要：提出一种直接得到脉宽小于50 as的单个脉冲的新方法.利用波长为800 nm脉宽为5fs的超短脉冲叠加上波长为10μm,强度为超短脉冲强度的10%且脉宽足够长的低频场脉冲驱动氦原子,谐波谱可以拓展到Ip+8.2Up,同时,高于4.2Up的谐波几乎是连续的.如果继续调节超短脉冲的载波包络相位,超连续谱可以继续拓宽,从而可以得到低于50 as的单个脉冲.We propose a new method to directly generate an isolated sub-50 attosecond pulse. The combination of a 5 fs driving laser pulse with the wavelength of 800 nm and a low frequency field with the wavelength of 10 μm is adopted. The intensity of the low frequency field is 10% that of the driving pulse. It is shown that the harmonic spectrum is extended to Ip ＋ 8.2Up and the harmonics above Ip ＋ 4.2Up become continuous. By adjusting the phase of the carrier-envelope of the few-cycle pulse, the bandwidth of the supercontinuum can be further broadened and a close-to-Fourier-limit sub-50 as pulse is directly obtained.

关 键 词：阿秒脉冲 超连续谱 低频场 超短脉冲 

分 类 号：TN78[电子电信—电路与系统]