Manipulation of self-organized nanograting for erasing and rewriting by ultrashort double-pulse sequences irradiation in fused silica

Abstract

Abstract The formation process of self-organized nanograting in fused silica glass with femtosecond laser (1 kHz, 120 fs, 800 nm) double-pulse sequences irradiation is investigated by combined control of polarization state of individual pulse, interpulse temporal delay (from −330 to 350 ps) and energy ratio in each sequence. It is found that the as-formed nanograting induced by the first pulse can be erased by the second pulse in repeated sequences irradiation, and moreover a new one is be rewritten in situ if the two pulses in a sequence were temporally well separated. The rewritten nanograting shows a new orientation perpendicular to the polarization direction of the second pulse. Additionally, the erasing and rewriting of nanograting can become more efficient as long as the second pulse energy increases to be higher than the first one, regardless of the interpulse delay. Our result shows that the energy ratio in double-pulse sequences plays a decisive role in the erasing and rewriting, because formation of nanograting mainly depends on the pulse energy deposition process. This study provides a useful reference for application of high-density data storage and amendment of nanograting.