基于光场强度关联的二阶时域Lau效应

Lau效应是非相干光照明下双光栅干涉形成的光学自成像现象.本文从描述光场传输的波方程出发,基于空间-时间对偶性,建立了时域光学系统脉冲响应函数与ABCD矩阵之间关系,在此基础上设计基于时域非相干光源光场强度关联的二阶Lau成像方案,最后得到描述二阶时域Lau效应的强度涨落关联表达式和周期性光脉冲的再现与介质的群延迟色散(GDD)参量之间的关系,并分析再现的周期性光脉冲的分布规律.结果 一方面表明周期性时域脉冲的非局域叠加再现源于关联光脉冲之间的联合色散,另一方面表明当两个时域光栅之间色散介质的群延迟色散参量等于Talbot群延迟色散参量的整数倍时,可获得周期性光脉冲成像.当两个时域光栅之间色散介质的群延迟色散参量等于二分之一Talbot群延迟色散参量的奇数倍时,可实现周期性光脉冲的重现但有半个周期的平移.该结果有助于促进光场强度关联在时域光学中的应用特别是周期性光脉冲在色散介质中的遥感传输.

Second-order temporal Lau effect based on optical field intensity correlation

Lau effect is a self-imaging phenomenon formed by the inference of dou ble-grating with incoherent illumination.In this paper,the relationship betwee n the impulse function and ABCD matrix of optical system in the time domain is a chieved based on the space-time duality from the wave equation describing the o p tical field.And then two schemes for second-order Lau effect via temporally op tcal field intensity correlation are designed.Finally,the intensity fluctuation correlation expressions describing second-order Lau effect are derived and th e relationship between the distribution of the reconstructed periodic temporal li ght pulses and the group delay dispersion (GDD) parameter of the dispersion medi um.Correspondingly,the distribution characteristics of the reconstructed light pulse pattern is analyzed.The results,on one hand,show that temporally perio dic structures are nonlocally superposed due to the joint dispersion of correlat ed light pulses.The results,on the other hand,show that when the GDD paramete r of dispersion medium between two gratings is an integral multiple of the Talbo t GDD parameter,the fringes of periodic light pulses are obtained.However,whe n the GDD parameter of dispersion medium between two gratings is an odd times of half the Talbot GDD parameter,the periodic pulses are reconstructed with a hal f period shift.Our results may be useful for the application of light field cor relation in temporal optics,especially for remotely transmitting the periodic t emporal signals robustly.