A metamaterial lens system for remote focusing and monitoring

Near-field focusing lenses are frequently constrained by the diffraction limit, necessitating the deployment of large aperture arrays to achieve both small focal spots and long focal lengths. In electromagnetic (EM) sensing applications, it is necessary to ensure that the path is unobstructed, which may lead to the internal sensing being affected by the external environment and even endanger personal safety in high-temperature sensing. In order to address the aforementioned issues, this paper presents a cascade lens system comprising two metamaterial lenses with varying structural characteristics. This configuration enables the focal length to be extended without the necessity for a particularly large array. Furthermore, the material of the secondary lens is quartz glass, which is resistant to high temperatures and serves to isolate the environment. At the same time, it can be used as a viewing window.