Spontaneous formation and optical manipulation of a woven domain fabric in a ferroelectric crystal.

Advances in ferroelectric materials, including engineered thin films and solid solutions, have enabled reliable photonic memory devices using switchable polarization states, providing fast, non-volatile, and energy-efficient optical data storage. Moreover, the ability to optically manipulate these encoded domain structures allows precise, reconfigurable light control, further enhancing photonic memory performance and versatility. We report the first observation of a robust, woven fabric of interlaced domains that spontaneously forms in bulk KTN:Li as it undergoes the ferroelectric phase transition, and demonstrate its local manipulation using focused light. The braided domain structure emerges as an extended irregular topologically-protected defect with an embedded distribution of locked-in charged domain walls, activation points that allow site-by-site manipulation using visible laser. Our discovery of woven fabric that can be optically addressed introduces a new route to achieve extended solid-state topologically-protected photonic memory.