2023/12/12 by Xiao Wu, Zhenzhong Hao, Wu, Xiao +15
Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #Applied Physics (physics.app-ph) #FOS: Physical sciences #Optics (physics.optics) #Photonic and Optical Devices #Photorefractive and Nonlinear Optics
paper · pdf · doi:10.48550/arxiv.2312.07024
openalex publication_date 2023/12/12 · openalex created_date 2023/12/14 · openalex updated_date 2026/07/28
Thin-film lithium niobate (TFLN) enables extremely high-efficiency second-order nonlinear optical effects due to large nonlinear coefficient d33 and strong optical field localization. Here, we first designed and fabricated a pulley-waveguide-coupled microring resonator with an intrinsic quality factor above 9.4 x105 on the reverse-polarized double-layer X-cut TFLN. In such a TFLN resonator without fine domain structures, second harmonic generation with an absolute (normalized) conversion efficiency of 30% (440,000% W-1), comparable to that in periodically poled lithium niobate (PPLN) microring resonators, was realized with a sub-microwatt continuous pump. This work reduces the dependence of high-efficiency nonlinear frequency conversion on PPLN microcavities that are difficult to prepare.