Microstructure-Induced Anisotropic Optical Properties of YF<sub>3</sub> Columnar Thin Films Prepared by Glancing Angle Deposition
Yao Shan,
Pian Liu,
Yao Chen,
Haotian Zhang,
Huatian Tu,
Yuxiang Zheng,
Rongjun Zhang,
Songyou Wang,
Jing Li,
Liangyao Chen
Affiliations
Yao Shan
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Pian Liu
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Yao Chen
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Haotian Zhang
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Huatian Tu
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Yuxiang Zheng
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Rongjun Zhang
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Songyou Wang
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Jing Li
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Liangyao Chen
Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures, Ministry of Education, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433, China
Yttrium fluoride (YF3) columnar thin films (CTFs) were fabricated by electron beam evaporation with the glancing angle deposition method. The microstructures and optical properties of YF3 CTFs were studied systematically. The YF3 films grown at different deposition angles are all amorphous. As the deposition angle increases, the columns in YF3 CTFs become increasingly separated and inclined, and the volume fraction of YF3 decreases, resulting in lower refractive indices. This phenomenon is attributed to the self-shadowing effect and limited adatom diffusion. The YF3 CTFs are optically biaxial anisotropic with the long axis (c-axis) parallel to the columns, the short axis (b-axis) perpendicular to the columns, and the other axis (a-axis) parallel to the film interface. The principal refractive index along the b-axis for the 82°-deposited sample is approximately 1.233 at 550 nm. For the 78°-deposited sample, the differences of principal refractive indices between the c-axis and the b-axis and between the a-axis and the b-axis reach the maximum 0.056 and 0.029, respectively. The differences of principal refractive indices were affected by both the deposition angle and the volume fraction of YF3.
