Ultrafast Laser Inducing Continuous Periodic Crystallization in the Glass Activated via Laser‐Prepared Crystallite‐Seeds

Abstract Tailoring ultrafast light–matter interaction as an enabler to create functional periodic crystalline patterns inside transparent dielectrics is of great scientific and technological significance but remains a tremendous challenge because of plenty of unclarified process details and physical mechanisms. Here, a dynamic process of ultrafast laser‐induced continuous periodic crystallization (CPC) to generate self‐organized crystal arrays (CAs) inside the glass is reported. The crystallite‐seeds induced by ultrafast laser are revealed to offer an auxiliary effect that can initiate and maintain the CPC process, which promises the high‐efficiency writing of CAs. The auxiliary effect originates from photo‐induced defects in the crystallite‐seeds, functions by drastically decreasing the pulse energy threshold for writing CAs, and can be manipulated by tuning the glass compositions and laser parameters. The created CAs are erasable and rewritable, which allows for potential applications in optical information encryption and data storage. This work not only opens up an avenue for creating embedded periodic crystalline patterns with extremely high efficiency but also helps to clarify the dynamics of ultrafast laser nanostructuring inside transparent dielectrics.