利用双层体光栅产生飞秒双脉冲  

Generation of Femtoscond Double Pulses by Two-Layer Volume Holographic Grating

作　　者：闫晓媛[1] 阎晓娜[2] 戴晔[2] 杨希华[2] 马国宏[2] 

机构地区：[1]长春理工大学电子信息工程学院通信工程系,吉林长春130022 [2]上海大学物理系超快光子学实验室,上海200444

出　　处：《光学学报》2013年第12期38-43,共6页Acta Optica Sinica

基　　金：国家自然科学基金(60908007;11274225;11174195);上海市重点学科项目(S30105);上海市教委创新基金项目(12YZ002)

摘　　要：基于Kogelnik耦合波原理和矩阵光学，讨论了调节双层体光栅的穿插层厚度产生飞秒激光双脉冲的方法。推导了飞秒脉冲读出双层体光栅后的衍射场表达式，数值模拟了瞬时衍射光强分布随穿插层厚度变化的关系曲线。数值模拟结果表明当穿插层厚度在4-11 mm区间变化时，衍射脉冲变成双脉冲，且双脉冲间隔与穿插层厚度成正比，利用衍射理论及衍射场表达式对其进行了解释。利用周期性介质群时延讨论了衍射脉冲时延随穿插层厚度的变化，发现脉冲间隔随穿插层厚度变化的斜率是脉冲时延随穿插层厚度变化斜率的绝对值的2倍。Based on Kogelnik′s coupled-wave theory and matrix optics, generation of femtosecond double pulses by modulating the thickness of buffer layer of two-layer volume holographic grating is discussed. The diffraction field expressions with a femtosecond pulse reading out the two-layer volume holographic grating are deduced. The relation curve of instantaneous diffraction intensity distribution varying with thickness of buffer layer numerically simulated. Simulation results show that when the buffer layer thickness changes from 4 mm to 11 mm, the diffraction pulse turns into double pulses and the interval between double pulses is linearly proportional to the thickness of the buffer layer. We use the diffraction theory and diffraction field expressions to give an explanation. At last, we discuss time delay of diffraction double pulses with respect to the thickness of the buffer layer by group time delay of periodic media, and it is shown that the slope of the pulse interval with respect to the thickness of the buffer layer is 2 times of that of pulse time delay.

关 键 词：激光光学 超短脉冲 体光栅 衍射 飞秒双脉冲 脉冲间隔 脉冲时延 

分 类 号：O436[机械工程—光学工程]