Scalable manufacturing and multi-modal cross-correlating characterization of low-dispersion bulk gradient refractive index chalcogenide glass-ceramics

The conversion of glasses into transparent glass-ceramic nanocomposites involves the complex challenge of balancing multiple competing factors such as the composition, size, and volume fraction of crystalline phases within a glass matrix. Especially, developing a singlet optical component with spatially varying properties, such as gradient refractive index (GRIN) materials, necessitates a new strategy on the scalable fabrication and multi-faceted characterization of glass-ceramics. Here, we employ Ge–As–Pb–Se chalcogenide glasses as a testbed and demonstrate a controlled crystallization strategy for their conversion into spatially tuned glass-ceramics. A first-ever combination of a simplistic yet widely applicable gradient thermal treatment and cross-correlating metrology is employed, creating scaled-up, minimally dispersive, and transparent GRIN materials with index gradients up to 0.1820 ± 0.0005. This work not only offers new insights into the complex crystallization behavior of glasses but also demonstrates a scalable approach to realizing spatially tailored monoliths, thus paving the way for practical optical applications.