Method for fabricating silica glass aspherical lenses combining layer-by-layer photopolymerization printing with real-time depth testing

This study proposes a method for real-time in situ testing of the "liquid glass" vertical printing parameters based on light-curing layer-by-layer printing technology. The method involves constructing an optical monitoring system on the side of the printing box, which allows for real-time observation of the printing structure formation process. By considering the effects of oxygen inhibition, demolding force, and other factors during the actual printing process, the most precise printing parameters can be obtained. Real-time monitoring enables dynamic adjustments to ensure optimal layer-by-layer printing. Based on these parameters, high-quality lens substrates with stepped structures can be printed without repeated corrections. Finally, a continuous, smooth "liquid glass" crescent surface is formed on the stepped substrate through meniscus post-processing, resulting in a silica glass aspherical lens after heat treatment. Experimental results show that the root mean square roughness (Rq) of the prepared silica glass lens is 4.49 nm, which exhibits excellent imaging performance. The testing method proposed in this study provides a new, to our knowledge, process route for the additive manufacturing of high-precision silica glass lenses, with broad application prospects.