CAJ | 학술논문

本文基于有限元法研究了直立生长于GaAs衬底的GaAs纳米线的光场响应和光场增强性质.实验使用多个波长的飞秒激光脉冲激发GaAs纳米线,测得了较高效率的二次谐波信号,并首次使用宽带超连续飞秒脉冲(1000—1300 nm)在纳米线上获取了宽带、无杂散荧光噪声的二次谐波信号.这种高效的二次谐波产生过程主要归因于纳米结构引起的局域场增强效应.本文阐明了GaAs纳米线的二次谐波倍频特性,这些结果对于其在纳米光学中的光器件、光集成等领域的进一步研究和实际应用具有很好的参考价值.
본문기우유한원법연구료직립생장우GaAs츤저적GaAs납미선적광장향응화광장증강성질.실험사용다개파장적비초격광맥충격발GaAs납미선,측득료교고효솔적이차해파신호,병수차사용관대초련속비초맥충(1000—1300 nm)재납미선상획취료관대、무잡산형광조성적이차해파신호.저충고효적이차해파산생과정주요귀인우납미결구인기적국역장증강효응.본문천명료GaAs납미선적이차해파배빈특성,저사결과대우기재납미광학중적광기건、광집성등영역적진일보연구화실제응용구유흔호적삼고개치.
The nonlinear optical properties of semiconductor nanowires are of vital importance in the researches of nano-optics and fabri-cation of nano-scale optoelectronic components. GaAs is a direct bandgap semiconductor material of wide bandgap, high electron mobility, large χ(2), high laser damage threshold and stable chemical properties, all of which make it a potential nonlinear optical material. In this report, based on the finite element method (FEM), we investigated the optical response and local field enhancement of GaAs nanowires perpendicular to the GaAs substrate surface. Under the radiation of femto-second laser pulses at different wave-lengths, efficient second harmonic generation (SHG) signal was acquired from the nanowires. Furthermore, noise-free broadband SHG signal was also detected to be excitated by super-continuous femto-second pulses (1000–1300 nm). The high-efficiency SHG process could be attribated mainly to the local field enhancement effect of the nanowires. Our investigation is the first, as far as we know, demonstrate the SHG properties of GaAs nanowires, and the results suggest that GaAs nanowires are promising in the potential applications in nano-scale optical devices, integrated nanophotonic circuits, from which related nano-optics researches can benefit.