Femtosecond laser writing of lithium niobate ferroelectric nanodomains

Lithium niobate (LiNbO3) is viewed as a promising material for optical communications and quantum photonic chips(1,2). Recent breakthroughs in LiNbO3 nanophotonics have considerably boosted the development of high-speed electro-optic modulators(3-5), frequency combs(6,7) and broadband spectrometers(8). However, the traditional method of electrical poling for ferroelectric domain engineering in optic(9-13), acoustic(14-17) and electronic applications(18,19) is limited to two-dimensional space and micrometre-scale resolution. Here we demonstrate a non-reciprocal near-infrared laser-writing technique for reconfigurable three-dimensional ferroelectric domain engineering in LiNbO3 with nanoscale resolution. The proposed method is based on a laser-induced electric field that can either write or erase domain structures in the crystal, depending on the laser-writing direction. This approach offers a pathway for controllable nanoscale domain engineering in LiNbO3 and other transparent ferroelectric crystals, which has potential applications in high-efficiency frequency mixing(20,21), high-frequency acoustic resonators(14-17) and high-capacity non-volatile ferroelectric memory(19,22).

Automated summary

Lithium niobate (LiNbO3) is a promising material for reconfigurable three-dimensional ferroelectric domain engineering, and recent breakthroughs in nanophotonics have advanced the development of high-speed electro-optic modulators, frequency combs, and broadband spectrometers. A non-reciprocal near-infrared laser-writing technique is demonstrated for nanoscale domain engineering in LiNbO3, providing a pathway for controllable domain engineering in transparent ferroelectric crystals.