Study on high performance infrared wide-band(7～11.5μm) antireflective film on germanium substrate

In order to enhance the transmission of germanium and mechanical feature of the antireflective film,the design and preparation of the high performance infrared wide-band antireflective film deposited on germanium substrate by ion-beam assisted deposition are investigated.The selection of film material,the design of film systems and the process of the ion-beam assisted deposition for the film systems are introduced.The measured spectral curves of the antireflection film at 7～11.5μm,deposited by this method,are given.The experimental results show that the peak transmission of the film is more than 99.5%,the average transmission in the designed wavelength range is greater than 97.5%,the film adherency is good,the optical and mechanical properties are stable.These are critical for the application of infrared optical systems.