GUO Wei,CHEN Huai-xi,ZHANG Xin-bin,LI Wen-jian,Choge，Dismas K,LI Guang-wei,LIANG Wan-guo.Broadband second-harmonic generation in a tapered PPLN waveguide[J].Optoelectronics Letters,2020,16(4):252-255 Broadband second-harmonic generation in a tapered PPLN waveguide Author Name Affiliation GUO Wei  Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China  CHEN Huai-xi  Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China  ZHANG Xin-bin  Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China  LI Wen-jian  Fujian Electronic Information Application Technology Institute Co., Ltd., Fuzhou 350002, China  Choge，Dismas K  Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China  LI Guang-wei  Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China  LIANG Wan-guo  Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China  Abstract:       We demonstrate a period poled tapered lithium niobate waveguide and study second harmonic generation (SHG) in this device for the purpose of broadening the quasi-phase matching (QPM) acceptance bandwidth. The finite-difference beam-propagation method is used to simulate the guided modes and calculate the effective indices. The simulation results show that by tapering the width of the cross section linearly, the phase mismatch between a specific input wavelength and its SHG signal can be varied along the propagation length. Ideal SHG phase-matching conditions for a wide range of input wavelengths in communication band from 1 542.5 nm to 1 553.5 nm can be satisfied in different positions of the waveguide. Hits: 1069 Download times: 0 View Full Text    Download reader