Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Opt Lett. 2012 Sep 1;37(17):3579-81. doi: 10.1364/OL.37.003579.
We report the synthesis of a nearly single-cycle (3.7 fs), ultrafast optical pulse train at 78 MHz from the coherent combination of a passively mode-locked Ti:sapphire laser (6 fs pulses) and a fiber supercontinuum (1-1.4 μm, with 8 fs pulses). The coherent combination is achieved via orthogonal, attosecond-precision synchronization of both pulse envelope timing and carrier envelope phase using balanced optical cross-correlation and balanced homodyne detection, respectively. The resulting pulse envelope, which is only 1.1 optical cycles in duration, is retrieved with two-dimensional spectral shearing interferometry (2DSI). To our knowledge, this work represents the first stable synthesis of few-cycle pulses from independent laser sources.
我们报告了一种近单周期（3.7fs）、78MHz 的超快光脉冲串的合成，该脉冲串通过被动锁模钛宝石激光（6fs 脉冲）和光纤超连续谱（1-1.4μm，8fs 脉冲）的相干组合产生。相干组合是通过平衡光互相关和平衡零差探测分别实现脉冲包络定时和载波包络相位的正交、阿秒精度同步来实现的。用二维光谱分束干涉法（2DSI）可以得到持续时间仅为 1.1 个光周期的脉冲包络。据我们所知，这项工作代表了首次从独立激光源稳定合成少周期脉冲。
