Rotating varifocal hyperspectral imaging system design method based on regularization band energy distribution

Moiré lenses offer a compact form factor and rapid focal-length tuning through the rotation of two conjugate sub-lenses to exploit diffractive effects. Although they have been applied in monochromatic, infrared, and terahertz zoom systems, the wavelength-dependent zoom characteristics resulted in rarely applying in hyperspectral systems. To remedy this situation, we propose an end-to-end achromatic varifocal hyperspectral imaging system design method that integrates an optical group (a diffractive optical element and moiré lens) with an energy-weighted spectral reconstruction algorithm. By rotating the moiré lens from 11° to 45°, continuous focal tuning from 20 to 40 mm is achieved over 420-660 nm, enabling an achromatic high-fidelity zooming hyperspectral reconstruction.