Author:
Zhang Chi,Tian Xiaohui,Liu Huaying,Duan Jiachen,Jia Kunpeng,Xie Zhenda,Zhu Shining
Abstract
Second-harmonic generation (SHG) is widely used for wavelength conversions in various applications including multi-wavelength lasers, imaging, and ultrafast optics. However, it remains a long-standing challenge to achieve both a broad SHG bandwidth and high efficiency due to the medium dispersion. Here, we propose an ultrabroadband efficient SHG on a lithium niobate on insulator (LNOI) platform by dispersion engineering. The waveguide cross section with two V-shaped grooves is carefully designed to minimize first- and second-order dispersion, which is feasible for current fabrication techniques. Due to the flattened dispersion, a record-high, to our knowledge, bandwidth-length product (
Δ
λ
⋅
L
) of
2444
µ
m
2
is achieved in a periodically poled 1.64-cm-long LNOI waveguide, which is four times the previously reported result. Such a scheme can also be generalized to SHG waveguides on other material platforms. Our results provide a new strategy of dispersion engineering for integrated photonics, and may be helpful for applications including frequency doubling, supercontinuum generation, and optical frequency combs.
Funder
National Natural Science Foundation of China
National Key Research and Development Program of China
Natural Science Foundation of Jiangsu Province
Key R&D Program of Guangdong Province
Guangdong Major Project of Basic and Applied Basic Research
Zhangjiang Laboratory
China Postdoctoral Science Foundation
Jiangsu Planned Projects for Postdoctoral Research Funds
Subject
Atomic and Molecular Physics, and Optics,Statistical and Nonlinear Physics