Characterization of optical properties of weak absorption thin film

Spectrum method is one of the important testing technique by which the optical properties (reflectance, transmittance and absorptance) of the thin film-substrate system could be obtained directly. The expressions for reflectance, transmittance and absorptance in case of weak absorption existing in substrate were derived by researching the optical transport characteristics of thin film-substrate system. The optical properties of thin film could be calculated by testing the properties of thin films deposited on single sided polishing substrate and double sided polishing substrate indirectly. HfO2 thin film deposited on fused silica substrate was measured by Lambda-900 spectrophotometer. And the error analysis shows that the error of single side reflectance is 1.00%, however, the error of single side transmittance is about 0.601%. It can be concluded that the characterization and evaluation of various types of single side thin film could be obtained by the method in this paper.