基于亚毫米尺度金属包覆波导的脉冲展宽

利用自由空间耦合技术,用超短脉冲激发亚毫米尺度对称金属包覆波导中的超高阶导模,提出一种脉冲展宽的新方法。由于超高阶导模的强色散性质,经过短距离的传输,即可使脉冲宽度迅速展宽。理论分析表明,1 ps的光脉冲在光波导中传输毫米量级距离后,脉冲展宽因子可达到1000倍。     

Simultaneously Large and Opposite Lateral Beam Shifts for TE and TM Modes on a Double Metal-Cladding Slab

We report simultaneously large and opposite Goos-Hanchen shifts for TE and TM beams on a double metalcladding slab. Theoretical examination shows that both positive and negative lateral shifts are in two orders of the wavelength. It is also found that the magnitude of the lateral beam shift strongly depends on the thickness of the upper metal layer. The optimal thickness of the upper metal layer for zero reflection is found to be the critical thickness above which a negative beam shift occurs. Numerical calculations are in good agreement with the theoretical results.     

N维氢原子四类升降算子的归一化系数

计算了N(d≥2)维氢原子四类升降算子的矩阵元,得到了N维氢原子归一化系数的普适表示式.当d=2或d=3时,得到二维与三维氢原子升降算子的归一化系数.     

光漂白聚合物波导折射率轮廓的确定

通过实验发现了光漂白聚合物薄膜厚度随光照时间按指数衰减的规律收缩,在此基础上,利用ｍ线法和精确的转移矩阵理论,由数值拟合得到的聚合物波导的折射率轮廓为费米函数。