Fluorescence Detection-Based Rapid Non-Destructive Testing of Large-Aperture Fused Silica Glass Components

As precision polishing and post-processing advance, surface-layer absorptive defects in fused silica optics increasingly show random distribution, low quantity, and ultra-low concentration—making efficient, non-destructive inspection of large-aperture components challenging. In this study, fused silica samples made by conventional ring polishing and acid cleaning were analyzed using photothermal weak absorption (PTWA), micro-X-ray fluorescence (μ-XRF), micro-X-ray diffraction (μ-XRD), and ultraviolet fluorescence microscopy spectroscopy. Results show that process-related contaminants emit strong spontaneous fluorescence between 500 and 620 nm under 375 nm ultraviolet (UV) excitation. Using this optical signature, a high-throughput detection system was developed that combines rapid fluorescence imaging for screening with PTWA for verification. Full-area scanning of a 100 mm × 100 mm sample successfully identified absorptive defects with significantly improved efficiency over conventional methods. This work provides a practical quality control solution for large-aperture fused silica optics and supports process optimization to reduce laser damage risks in high-performance systems.