Proceedings Article | 18 December 2023
KEYWORDS: Image resolution, Imaging systems, Biological imaging, Diffraction, Design and modelling, Chromatic aberrations, Visible radiation, Lenses, Light sources, Optical imaging
The optical imaging technology possesses characteristics such as intuition, high resolution, and convenient application, which are of significant importance in the fields of physics, materials science, biology, and medicine. Traditional imaging systems are large in volume, heavy in weight, and structurally complex. Recently, the development of Multi-level Diffractive Lens (MDL) has introduced advantages such as small volume, light weight, and easy integration. However, the current analysis of MDL imaging quality has generally been limited to a narrow spectral range, and the aperture sizes of the components are mostly in the millimeter range, which somewhat restricts their applications. This study focuses on the research of the imaging performance of a 5cm aperture MDL. To analyze the focusing performance and imaging quality, we designed and constructed an optical setup that is compatible with a 10cm aperture. The tested wavelength range covers 0.4 to 1.1 μm. The test results show that the RMS value of the focal length for the large aperture MDL is 22.67cm in the visible and near-infrared wavelength ranges. Compared to the traditional Fresnel lens, achromatism performance is significantly improved. The RMS value of the focal spot size in the visible wavelength range is 24.01μm, while in the near-infrared wavelength range is 26.64μm. The full-band imaging test results in the range of 0.4to 1.1μm show that the large aperture MDL has a line pair resolution of 161.01 lp/mm and a linewidth resolution of 3.1lp/mm. The aforementioned experimental results demonstrate the wide range of potential applications for the large aperture MDL in fields such as microscopic analysis, optoelectronic detection, and medical
