Study On Ion Assisted Deposition Low Loss TiO₂ Optical Thin Film

Titanium dioxide(TiO₂),as a high-priced oxide of titanium,is a wide band-gap oxide semiconductor material,which has the characteristics of stable structure,good mechanical properties,and excellent chemical stability.Because of its excellent chemical and physical properties,it has been widely used in photocatalysis,solar energy utilization,gas sensor,and other fields.When titanium oxide is used as an optical thin-film material,it has a high refractive index and high transmittance in the visible and near-infrared region of the spectrum.Because of its excellent optical properties,it has been gradually widely used in the field of the optical thin film.Carried out on low loss of TiO₂ thin film optics related research has very important significance,this article in view of the titanium oxide optical thin film from film absorption characterization method,based on the intelligent algorithm of thin film optical constants and different ion beam assisted preparation,separation of the body and the surface scattering,and loss of characterization of multilayer film was prepared.The main achievements include:1.For the laser calorimetry used in the measurement of optical film absorption loss,when the optical film element tested has a large scattering,the film produces stray light to irradiate the temperature sensor,which will lead to a great difference between the measured optical film absorption loss and the actual absorption loss.To solve this problem,an optical film absorption test method based on an infrared thermal imager is proposed in this paper.The infrared thermal imager obtains the temperature change of the optical film during laser irradiation,avoiding the influence of scattered light,and uses the finite element method to solve the optical absorption.The whole test process is fast and flexible.2.Thanks to the development of intelligent algorithms in recent years,there are more and more applications of computer iterative optical film optical constants in film optics.Based on the particle swarm algorithm,this paper uses the MATLAB platform to design software for solving optical film optical constants and physical thickness.,The software can be used for the characterization of film performance during the development of the optical coating process.3.The effects of four parameters,including ion source bias,vacuum chamber oxygen flow,deposition rate,and substrate temperature,on the optical loss of titanium oxide thin films were experimentally studied when the ion beam assisted the preparation of TiO₂ optical films.The volume scattering and surface scattering of the TiO₂ optical film are distinguished by the experimental method of film system design.4.Based on the loss theory of single-layer TiO₂ optical film,the TiO₂/SiO₂ high-reflective film in the 632.8nm and 1064 nm bands are designed in this paper,and the optical loss of the high-reflective film is tested and characterized.For a high-reflection film with a design wavelength of 632.8nm,the measured reflectivity can reach more than 99.88%,and for a high-reflection film with a design wavelength of 1064 nm,the measured reflectivity is more than 99.98%.