Design of a broadband dual-channel panoramic system with a double-layer diffractive optical element

This study presents a dual-channel panoramic annular lens (PAL) system operating over 450-1550 nm for blind-area-free continuous imaging. The field of view (FoV) of the panoramic channel is 360^∘×(35^∘-90^∘), while the front channel covers 360^∘×(0^∘-35^∘). A double-layer diffractive optical element (DLDOE) is incorporated to compensate for broadband chromatic aberration. Considering the angular characteristics of the dual-channel system, the DLDOE is optimized based on the comprehensive bandwidth integral average diffraction efficiency (CBIADE), achieving angle-bandwidth-averaged diffraction efficiencies of 97.95% and 98.08% for the panoramic and front channels, respectively. The designed PAL system exhibits a compact structure and high imaging performance. The modulation transfer function (MTF) exceeds 0.51 for the panoramic channel and 0.30 for the front channel at 100 lp/mm, while the F-θ distortion is less than 3.88%. Our proposed design provides promising insights for the application of panoramic systems in challenging, low-illumination imaging scenarios, such as security surveillance and autonomous driving.