CAJ | 학술논문

利用平面波展开法和时域有限差分法,模拟研究了基于自准直条件下的高斯光束入射光子晶体Kretschmann结构时发生的同时具有正向和负向Goos-H¨anchen位移的双束反射现象.研究表明,反射光束中具有一束较小的正向位移,而另一束具有较大的负向位移,发现当Kretschmann结构支持的泄漏的表面模式被激发时才出现这一特殊现象;表面模式的场分布说明介质波导中存在着强局域稳态场,大的位移来自于表面模式与自准直体模式间的强耦合,同时探讨了表面模式与光子晶体自准直体模式之间发生耦合的条件和影响参数.本文负向位移最大达到?23.23a (a为晶格常数),对应入射光波长的4.99倍,是束腰半径的1.1615倍.
이용평면파전개법화시역유한차분법,모의연구료기우자준직조건하적고사광속입사광자정체Kretschmann결구시발생적동시구유정향화부향Goos-H¨anchen위이적쌍속반사현상.연구표명,반사광속중구유일속교소적정향위이,이령일속구유교대적부향위이,발현당Kretschmann결구지지적설루적표면모식피격발시재출현저일특수현상;표면모식적장분포설명개질파도중존재착강국역은태장,대적위이래자우표면모식여자준직체모식간적강우합,동시탐토료표면모식여광자정체자준직체모식지간발생우합적조건화영향삼수.본문부향위이최대체도?23.23a (a위정격상수),대응입사광파장적4.99배,시속요반경적1.1615배.
We perform the finite-difference time-domain (FDTD) simulations and analyze a dual-beam-reflection phenomenon for a Gaus-sian beam illuminating a Kretschmann configuration composed of a lossless dielectric waveguide between a photonic-crystal-made prism and air. One reflection beam has a small positive shift and the other has a large negative shift in the dual-beam-reflection phe-nomenon. The FDTD shows that the specific phenomenon takes place just when the corresponding leaky surface mode supported in the Kretschmann configuration is excited. Field profile of the surface mode demonstrates a strong localized stationary field in the dielectric waveguide. We find that the maximum negative lateral shift is?23.23a, corresponding to 4.99 times of the incident wavelength, which is 1.1615 times of the beam waist.