| Summary: | Fabricating materials with specific refractive indices, which do not naturally exist in the nature, has always been an issue. This paper presents a method for fabricating SiO<sub>x</sub> films with specified refractive index. It is well known that the refractive index of reactively sputtered SiO<sub>x</sub> films depends on its deposition conditions; in this paper, this fact was employed to fabricate films with arbitrary refractive indices. A statistical study and a Genetic Algorithm are implemented that can determine the deposition conditions (including oxygen partial flow and pressure) for fabricating a film with an arbitrary refractive index in the range of 1.4-4.2. The method was experimentally shown to correctly determine the deposition conditions. The functionality of using the proposed method in fabricating optical components was further evaluated by fabricating a distributed Bragg reflector (DBR) consisting of 4.5 pairs, whose refractive indices of the layers were determined by the proposed method. The DBR featured a high 95% reflection in a bandwidth of more than 270 nm, which can be categorized as a high-quality DBR. The advance of the proposed method is that the films are made from a single target source without making any physical changes in the target or substrate positions.
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