3-D Printing Disordered-Cavity-Based Metaimager for Coincidence Imaging

A disordered-cavity-based metaimager (DCM) that can be used for coincidence imaging is proposed in this letter. The proposed DCM possesses narrow frequency gap, low correlation coefficients, and high efficiency. Due to the all-in-one design, the DCM has good robustness and is insensitive to fabrication errors, which is suitable to be fabricated using the 3-D printing technique. The DCM working from 32 to 36 GHz contains a disordered cavity, sets of high-efficiency coupling slots and a frequency-diverse metasurface. Measurement modes generated by the DCM are low correlated due to frequency-diverse field distributions of the disordered cavity and distinguished transmission features of metamaterial elements composing the metasurface. Performances of the DCM including the reflection coefficients, the efficiency, and the correlation coefficients are evaluated. Finally, a coincidence imaging experiment is also carried out using the proposed DCM and the image of the target is reconstructed under different signal-to-noise ratio (SNR) conditions. The design is validated by both the simulated and measured results.