Pb_(1 - x) Ge_x Te薄膜的光学性质

OPTICAL PROPERTIES OF Pb _( 1- x ) Ge _ x Te FILMS ZHANG Su Ying FAN Bin LI Bin

对 PVD沉积 Pb1 - x Gex Te薄膜研究发现 Pb1 - x Gex Te是一种高性能的红外材料 ,在 3～ 2 5μm光谱范围具有较好的透光性能 ,室温下的折射率为 4.8～ 5 .6 .薄膜的光学性质 ,包括透射率、色散关系以及折射率的温度系数dn/ d T,与材料中组分 x、环境温度和薄膜的沉积工艺条件有密切关系 .适当地改变组分和工艺条件 ,可以使薄膜的折射率温度系数 dn/ d T从负变到零并转为正 。

Study of Pb1-xGexTe films deposited by PVD revealed that Pb1-xGexTe is a kind of fine characteristic infrared materials, which has a high transmission in the spectral range 3 similar to 25 mum, and has indices of refraction in the range 4.8 similar to5.6 at room temperature. Optical properties, which include transmission spectrum, dispersion spectrum and temperature coefficient dn/dT of refractive index, depend strongly on content x, environmental temperature and deposition conditions. It can be found that proper change of content x and deposition conditions may result in the change of temperature coefficient dn/dT of refractive index from negative to zero, and to positive from zero, which is of significance for manufacturing highly stable infrared optical filters.