Asymmetric coherent rainbows induced by liquid convection  

作　　者：Tingting Shi Xuan Qian Tianjiao Sun Li Cheng Runjiang Dou Liyuan Liu Yang Ji 施婷婷;钱轩;孙天娇;程力;窦润江;刘力源;姬扬(State Key Laboratory for Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China;College of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]State Key Laboratory for Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China [2]College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China [3]College of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [4]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics B》2021年第12期450-454,共5页中国物理B（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301202);the National Natural Science Foundation of China(Grant Nos.11674311 and U20A20205)。

摘　　要：Coherent rainbows can be formed by focusing white-light laser into liquids.They are bilaterally symmetric interference rings with various shapes.Such interference rings arise from the temperature distribution of the liquid induced by laser heating,i.e.,thermal lens effect,which changes the refractive index locally and thus the optical path difference.The up-down asymmetry of the interference rings is caused by convection in the liquid.With the increase of the viscosity,the interference rings change their shape from oval to circular shape.After a shutter is opened and the laser shines into the liquid,the interference rings are circular at the beginning.As time goes on,they gradually turn into an oval shape.Let the liquid go a free-fall at the beginning,the interference rings remain circular.All the three experiments have confirmed that the asymmetric interference rings are due to convection in the liquid associated with thermal lens effect.We also numerically simulate the two-dimensional heat conduction with and without convection,whose results agree well with our experimental observations.

关 键 词：coherent interference thermal lens effect CONVECTION numerical simulation 

分 类 号：TN24[电子电信—物理电子学]