摘要
设计了一种工作在光波段的新型四重对称的双层手征结构,通过数值模拟得到透射系数和反射系数,反演计算了结构的圆二色性、旋光角、手征参数和折射率。结果表明该结构在谐振波长附近具有很强的旋光性,并且在椭偏度为零时,即透射光变成完全线偏振光时,旋光角达到了55°;在一定波段内可以实现左旋圆偏振光(LCP)和右旋圆偏振光(RCP)的负折射率,且不需要介电常数和磁导率同时为负,更重要的是,实现负折射率的左旋圆偏振光(LCP)具有较宽的频带,不局限于谐振波长附近,在椭偏度为零时,折射率也为负。考虑到具体的实验制作,对加衬底的手征结构进行了数值模拟,结果表明谐振波长向长波长方向产生了偏移,完全线性偏振光的旋光角仍然有40°。
A new four-fold symmetry double-layer chiral structure is designed, of which the operating wavelength band is in optical region. The transmission and reflection coefficients are obtained by numerical simulation, then the circular dichroism, polarization azimuth rotation angle, chiral parameter, refractive index of the structure are calculated. The results show that giant optical activity is found at the resonance wavelength region, and when the ellipticity is zero, the transmitted light becomes linearly polarized light completely, the polarization azimuth rotation angle reaches 55°. It is found that the negative indexes of the left-handed circularly polarized （LCP） and right-handed circularly polarized （RCP） waves can be realized without negative permittivity and permeability simultaneously. Most importantly, the negative index of the LCP can be achieved in wide band, which is not limited at resonance wavelength region. When the ellipticity is zero, the negative index also can be achieved. Taking into account the experimental manufacture, the substrate is added in the chiral structure. The simulated results demonstrate that resonance wavelength regions shift to long wavelength, and the polarization azimuth rotation angle still has 40° when the transmitted light becomes linearly polarized light completely.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2014年第1期175-180,共6页
Acta Optica Sinica
基金
国家自然科学基金(61078060)
宁波市科技创新团队(2009B21007)
宁波大学王宽诚幸福基金
关键词
材料
手征
手征参数
负折射率
materials
optical region
chiral parameter
negative refractive index
