In order to achieve accurate prediction of subsurface damage (SSD) in ultra-precision grinding of high-performance ultra-violet laser-irradiated fused silica optics, the paper combines damage precursor multimodal measurement technology with magnetorheological finishing spot method detection. Various methods such as photothermal weak absorption and fluorescence confocal imaging are used for measuring the surface roughness and subsurface damage depth of a series of fused silica samples prepared under different ultra-precision grinding parameters. The correlation between surface roughness and subsurface damage depth in ultra-precision grinding based on laser damage performance is established using curve fitting. The results indicate that there is a metamorphic layer below the subsurface crack layer, which can cause additional photothermal absorption. Subsurface damage is constituted of the subsurface crack layer and metamorphic layer. Under ultra-precision grinding conditions, the maximum depth of subsurface damage is generally 2.00–4.22 times the depth of the subsurface damage cluster. The roughness Ra and the subsurface damage cluster depth correspond to SSD_(cluster) = 195 × Ra − 0.13. The maximum depth of subsurface damage can be predicted by measuring the Ra value, by which accurate prediction of defect depth in ultra-precision grinding and guiding the high-performance manufacturing of ultra-violet laser-irradiated fused silica optics can be achieved.

Liquid crystals based on dispersions of two-dimensional (2D) materials have recently been developed for light modulation, exhibiting superior performances compared to conventional organic liquid crystals in a variety of prototypical applications, including coloration, solar-blind communications and blue-light fluoresce. Among the diverse family of 2D liquid crystals, vermiculite-based liquid crystals stand out with advantages in low cost, ease of mass production and environmental sustainability, owing to the high natural abundance of the material. Here, we demonstrated magnetic-field tunable optics with 2D vermiculite dispersions prepared through a facile ‘exchange and redispersion’ method. By exploiting the intrinsic ion-exchange capability of clay minerals, we observed a significantly enhanced magneto-birefringence of the vermiculite dispersion upon replacing the native cations with magnetic ions, manifesting in a doubled Cotton–Mouton coefficient, representing the highest value among previous reports. Magnetization measurements reveal that there is a remarkable magnetic anisotropy in Fe ion-exchanged vermiculite samples in contrast to the isotropic magnetism of pristine vermiculite, which accounts for the observed enhancement of magneto-birefringence. Our findings demonstrate that ion exchange can serve as a simple and effective strategy to modulate the physical and chemical properties of 2D materials’ dispersions, thereby opening avenues for broader and more diverse applications.