Fabrication and performance of high refractive index achromatic gradient index chalcogenide glass

Gradient index (GRIN) glasses utilize a specially tailored internal refractive index combined with the designed surface curvature of the optical element to enhance the correction of chromatic and spherical aberration. Additionally, GRIN technology can significantly improve imaging quality and better match high-performance detectors. In this study, we used an evaluation function model to determine the required properties of the base materials and fabricated a series of Ge25Se75-xTex glasses, identifying the optimal combination for chromatic aberration correction. A novel GRIN glass was fabricated using the hot-press diffusion method, and its internal refractive index was shaped into a curvature profile through molding. We analyzed the refractive index distribution of the GRIN lens and evaluated its imaging performance. Additionally, by comparing the imaging performance of the GRIN lens with that of a homogeneous lens, we demonstrated the chromatic aberration correction capabilities of the GRIN lens.