基于独立飞秒激光源的长时间稳定的相干脉冲合成

项目名称： 基于独立飞秒激光源的长时间稳定的相干脉冲合成

项目编号： No.11274239

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 宋有建

作者单位： 天津大学

项目金额： 90万元

中文摘要： 相干脉冲合成是超快科学与技术的重要工具，可以实现单周期甚至亚周期的超短激光脉冲合成、任意波形或任意光谱形状产生、以及能量合束等功能，对原子尺度的超快动力学的研究、超宽带信息处理、强场物理等领域具有极高的价值。从时间域上讲，有效的飞秒激光脉冲相干合成要求脉冲包络与包络之下的激光电场严格匹配。或者对应到光谱域：飞秒激光频率梳的梳齿严格重合，即具有完全相同的纵模间隔与载波包络偏移频率。本项目提出一种独立飞秒激光源的相干脉冲合成方案：基于平衡光学互相关方法锁定重复频率，利用前馈锁相技术在谐振腔外消除两台飞秒激光器间的载波包络相位差，重复频率与载波包络偏移频率的锁相环相互独立，将两台飞秒激光源的脉冲包络之间的时间抖动及载波包络偏移相位之间的时间抖动均降低至阿秒量级，实现高质量的长时间稳定的相干脉冲合成。

中文关键词： 飞秒激光；相干合成；载波-包络相位；时间抖动；阿秒

英文摘要： Phase coherent ultrashort laser pulse synthesis is an important tool for ultrafast science and technology, which enables single cycle or even sub-cycles ultrashort laser pulse synthesis, arbitrary waveform or spectrum generation, and high energy targeted laser beam combination, has substantial applications on the dynamical study of atom scale ultrafast phenomenon, super wideband signal processing and strong field physics. In the time domain, effective phase coherent ultrashort laser pulse synthesis requires exact match of pulse envelopes and the underneath electrical fields. Or equivalently in the optical frequency domain, the longitude modes of the frequency combs should exactly match, that is, the two combs should have same longitude mode spacing and same carrier envelope frequency. A novel method for phase coherent pulse synthesis of independent femtosecond laser sources is proposed in this application: the repetition rate of the two lasers are locked by balanced optical cross correlation method, and the differential carrier envelope phase of the two lasers is canceled outside the laser cavity by a feed forward phase locking scheme. The two phase locked loops are completely orthogonal with each other, which results in a high quality and low drift phase coherent pulse synthesis, with several tens of attosecond

英文关键词： femtosecond laser；coherent synthesis；carrier-envelope phase；timing jitter；attosecond