基于倾斜沉积薄膜材料的双折射特性,采用单一TiO2设计和制备了中心波长为632 nm的双折射消偏振膜。首先以60°和70°的沉积角度镀制了TiO2单层膜,通过单层膜的透射光谱分别拟合出两种沉积角度下薄膜对s和p偏振光的等效折射率nPH,nSH和nPL,nSL。通过对折射率的组合,实现正入射时s偏振光透射率大于p偏振光,而入射角度增大会使两者透射率差值减小,基于这一思想设计并制备了消偏振膜。分别测量了消偏振薄膜在400-800 nm波段范围内正入射及倾斜入射条件下s和p偏振光的透射光谱。入射角为60°时,s偏振光反射带宽基本与p偏振光反射带宽重合,在波长632 nm左右基本实现消偏振。结果表明,利用材料的双折射特性,可以设计和制备出倾斜入射条件下消偏振薄膜。

Based on the birefringent characteristic of thin film fabricated by glancing angle deposition(GLAD),a birefringent non-polarizing thin film at wavelength 632 nm only using titanium oxide is designed and deposited. At the beginning,two titanium oxide monolayers were deposited with the deposition angle 60° and 70° respectively. The effective refractive index of the monolayer for s- and p-polarization,nPH,nSH and nPL,nSL ,were obtained. a higher s transmittance than p polarization at normal incidence is got by arranging the index correctly,since the increase of the incidence would bring an opposite effect,we could get a non-polarizing effect at a very angle can be got. Based on the analysis above,a non-polarizing thin film was designed and prepared. The s- and p-polarization transmission spectra of non-polarizing film were measured with photometer at normal and tilted incidence. At the incidence angle of 60°,the reflection band width of s- and p-polarizations were less different and the non-polarizing effect was achieved partially. The obliquely incident non-polarizing thin film can be designed based on the thin film material′s birefringence.