可见近红外双波段增透膜的设计及制备

Design and Fabrication of Visible and Infrared Dual-band AR Coating

以K9为基底设计了一种覆盖部分可见及近红外双波段的增透膜,即:增透波长包括0.55～0.78μm和1.0～1.3μm两个波段。工艺实现采用了电子束蒸发物理气相沉积的方法,薄膜材料仅含有TiO2和SiO2,并分别作为高低折射率材料。利用岛津分光光度计对双面镀制该膜系样品的透过率进行测量,测试结果表明0.55～0.78μm波段平均透过率为98.01%,1.0～1.3μm波段平均透过率达到97.04%。通过SEM的膜层截面证实实际膜层厚度相对于设计值来说偏厚,致使透射率光谱曲线略往长波方向漂移,但所需波段内平均透过率仍可满足所需光学特性。环境测试表明:薄膜具有良好的稳定性和牢固度。该增透膜可以应用于可靠性要求较高的环境中。

A typle of visible（0. 55-0. 78 μm） and infrared（1. 0-1. 3 μm） band AR coatings were designed on K9 substrate. The coatings were fabricated by electron beam physical vapor deposition（EBPVD）. Two types of coating materials titanium oxide（TiO2） and silicon oxide（SiO2） which were treated as high index and low index material respectively were used in this process. Shimadzu spectrophotometer was used to measure the transmittance of the the sample which was coated by the antireflection coatings on both side. The test result indicates that its average transmittance is about 98. 01%in the spectrum of 0. 55-0. 78 μm and 97. 04% in the spectrum of 1. 0-1. 3 μm. The thickness of deposited layers is thicker than designed one,which is verified by SEM cross section. Hence,there is a little drift towards long wavelength with the curve of spectrum. And the test of the design band can well accord with the designing result. Measurement of stability and firmness indicates the coatings have good performance. It makes it possible to be used in some rigorous environment.