Fluctuations of optical phase of diffracted light for Raman–Nath diffraction in acousto–optic effect  

作　　者：翁存程 章小曼 

机构地区：[1]College of Physics and Energy,Fujian Normal University [2]Key Laboratory of Opto-Electronic Science and Technology for Medicine of Ministry of Education [3]College of Photonic and Electronic Engineering,Fujian Normal University

出　　处：《Chinese Physics B》2015年第1期293-297,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.61178089);the Science and Technology Program of the Educational Office of Fujian Province of China(Grant Nos.JB12012 and JB13003)

摘　　要：The Raman–Nath diffraction in acousto–optic effect was studied theoretically and experimentally in the paper. Up to now, each order of diffracted light in Raman–Nath diffraction was still considered simply to be just frequency-shifted and to be a plane wave. However, we find that the phase and frequency shifts occur simultaneously and individually in Raman–Nath diffraction. The findings demonstrate that, in addition to the frequency shift, the optical phase of each order of diffracted light is also shifted by the sound wave and fluctuates with the sound wave and is related to the location in the acoustic field from which the diffracted light originates. As a result, the wavefront of each order of diffracted light is modulated to fluctuate spatially and temporally with the sound wave. Obviously, these findings are significant for applications of Raman–Nath diffraction in acousto–optic effect because the optical phase plays an important role in optical coherence technology.The Raman–Nath diffraction in acousto–optic effect was studied theoretically and experimentally in the paper. Up to now, each order of diffracted light in Raman–Nath diffraction was still considered simply to be just frequency-shifted and to be a plane wave. However, we find that the phase and frequency shifts occur simultaneously and individually in Raman–Nath diffraction. The findings demonstrate that, in addition to the frequency shift, the optical phase of each order of diffracted light is also shifted by the sound wave and fluctuates with the sound wave and is related to the location in the acoustic field from which the diffracted light originates. As a result, the wavefront of each order of diffracted light is modulated to fluctuate spatially and temporally with the sound wave. Obviously, these findings are significant for applications of Raman–Nath diffraction in acousto–optic effect because the optical phase plays an important role in optical coherence technology.

关 键 词：Raman–Nath diffraction acousto–optic effect phase shift frequency shift 

分 类 号：O436.1[机械工程—光学工程]