• Special Issue
  • Lithium Niobate Based Photonic Devices
  • 15 Article (s)
Editorial for special issue on lithium niobate based photonic devices
Feng Chen, and Yuping Chen
Lithium niobate (LiNbO3), so-called “Silicon in Photonics,” is a multifunctional crystal with a combination of a number of excellent physical properties. In optics and photonics, the LiNbO3-based devices, such as modulators, wavelength converters, waveguide amplifiers, and quantum photonic chips, have been realized and widely applied in various areas. In addition to the traditional waveguides, the LiNbO3 on insulators (LNOI) technology enables fabrication of large-scale, high-quality LiNbO3 thin film wafers, boosting the development of thin film LiNbO3-based devices; consequently, versatile applications have been realized to satisfy the small footprint for photonic integrated circuits (PICs). Aiming to present the impressive progresses in this field, Chinese Optics Letters publishes this special issue focusing on the fabrication of new LNOI wafers, new design of LNOI-based structures, and the intriguing applications of LNOI-based devices in selected active topics.
Chinese Optics Letters
  • Publication Date: Jun. 10, 2021
  • Vol.19 Issue, 6 060001 (2021)
Efficient second harmonic generation in silicon covered lithium niobate waveguides
Bin Fang, Shenglun Gao, Zhizhang Wang, Shining Zhu, and Tao Li
Chinese Optics Letters
  • Publication Date: Jun. 10, 2021
  • Vol.19 Issue, 6 060004 (2021)
Polarization diversity two-dimensional grating coupler on x-cut lithium niobate on insulator
Renyou Ge, Hao Li, Ya Han, Lifeng Chen, Jian Xu, Meiyan Wu, Yongqing Li, Yannong Luo, and Xinlun Cai
We propose and demonstrate a polarization diversity two-dimensional grating coupler based on the lithium niobate on insulator platform, for the first time, to the best of our knowledge. The optimization design, performance characteristics, and fabrication tolerance of the two-dimensional grating coupler are thoroughly analyzed utilizing the three-dimensional finite-difference time-domain method. Experimentally, -7.2 dB of coupling efficiency is achieved with 1 dB bandwidth of 64 nm. The polarization-dependent loss is about 0.4 dB around 1550 nm. Our work provides new polarization multiplexing approaches for the lithium niobate on insulator platform, paving the way for critical applications such as high-speed polarization multiplexed electro-optical modulators.
Chinese Optics Letters
  • Publication Date: Jun. 10, 2021
  • Vol.19 Issue, 6 060006 (2021)
On-chip erbium-doped lithium niobate waveguide amplifiers [Invited]
Qiang Luo, Chen Yang, Zhenzhong Hao, Ru Zhang, Dahuai Zheng, Fang Bo, Yongfa Kong, Guoquan Zhang, and Jingjun Xu
Chinese Optics Letters
  • Publication Date: Jun. 10, 2021
  • Vol.19 Issue, 6 060008 (2021)
High-Q lithium niobate microring resonators using lift-off metallic masks [Invited]
Ke Zhang, Zhaoxi Chen, Hanke Feng, Wing-Han Wong, Edwin Yue-Bun Pun, and Cheng Wang
High-Q lithium niobate (LN) optical micro-resonators are an excellent platform for future applications in optical communications, nonlinear optics, and quantum optics. To date, high-Q factors are typically achieved in LN using either dielectric masks or femtosecond laser ablation, while the more standard and commonly available lift-off metallic masks are often believed to lead to rough sidewalls and lowered Q factors. Here, we show that LN microring resonators with strong light confinement and intrinsic Q factors over 1 million can be fabricated using optimized lift-off metallic masks and dry etching processes, corresponding to a waveguide propagation loss of ~0.3 dB/cm. The entire process is fully compatible with wafer-scale production and could be transferred to other photonic materials.
Chinese Optics Letters
  • Publication Date: Jun. 10, 2021
  • Vol.19 Issue, 6 060010 (2021)
Nonlinear Talbot self-healing in periodically poled LiNbO3 crystal [Invited]|On the Cover
Bingxia Wang, Shan Liu, Tianxiang Xu, Ruwei Zhao, Peixiang Lu, Wieslaw Krolikowski, and Yan Sheng
The nonlinear Talbot effect is a near-field nonlinear diffraction phenomenon in which the self-imaging of periodic objects is formed by the second harmonics of the incident laser beam. We demonstrate the first, to the best of our knowledge, example of nonlinear Talbot self-healing, i.e., the capability of creating defect-free images from faulty nonlinear optical structures. In particular, we employ the tightly focused femtosecond infrared optical pulses to fabricate LiNbO3 nonlinear photonic crystals and show that the defects in the form of the missing points of two-dimensional square and hexagonal periodic structures are restored in the second harmonic images at the first nonlinear Talbot plane. The observed nonlinear Talbot self-healing opens up new possibilities for defect-tolerant optical lithography and printing.
Chinese Optics Letters
  • Publication Date: Jun. 10, 2021
  • Vol.19 Issue, 6 060011 (2021)

Chinese Optics Letters (COL) invites original articles for a Special Issue on Lithium Niobate Based Photonic Devices to be published in June 25 2021. Lithium niobate (LiNbO3) is a multifunctional crystal with combination of a number of excellent properties, such as electrooptical, acousto-optic, nonlinear optical, piezoelectric, and pyroelectric features. In optics and photonics, the LiNbO3-based devices have been widely applied in various aspects. Typical applications include acoustic- and electro-optic modulators, nonlinear wavelength converters, waveguide amplifiers, and quantum memories. The traditional LiNbO3 based photonic devices are constructed on micro-photonic structures, e.g., optical waveguides. A number of techniques have been utilized to produce low-loss LiNbO3 waveguides towards diverse applications. Recently, thin-film devices based on LiNbO3-On-Insulators (LNOI) technology have emerged as promising candidates due to the on-chip integration and strong confinement of light fields. Exciting LNOI-based devices, such as high speed modulators, highly efficient nonlinear optical elements, or hybrid quantum chips, have been developed through advanced techniques, showing distinguished performance for practical applications. There are continuous interests amid researchers on LiNbO3-based photonic devices and related applications, and a number of research groups are devoted to these interesting works. Regarding to these efforts and achievements, the scope of this special focus, covers all aspects of recent theoretical and experimental research related to LiNbO3–based photonic structures and devices. Specific areas of interest include, but not limited to: