超构材料类电磁感应透明现象的实验研究

Electromagnetically Induced Transparency in Metamaterials

基于梳状线和开口谐振环组成的耦合结构,在开口谐振环上加载电阻调节损耗,加载电容使结构达到深亚波长尺度,实现了超构材料类电磁感应透明现象。通过调节梳状线和开口谐振环之间的距离改变近场耦合强度。实验结果表明,随着耦合强度的减小,电磁感应透明频率处的透射率逐渐减小,反射率逐渐增大,吸收率呈现先增大后减小的趋势。与此同时,群延时变大,慢波效应明显,但透明窗口逐渐变窄,慢波带宽变窄。

Electromagnetically induced transparency(EIT)was studied experimentally in a waveguide system with different coupling strength.A deep-subwavelength EIT element consisting of a comb line and a split-ring resonator was put forward,where the coupling strength was adjusted by changing the distance between the comb line and the split-ring resonator.At the EIT frequency,when the coupling strength becomes weaker,the reflectance is higher,the transmittance is lower and the absorbance is first higher then lower.Weaker coupling creates a narrower transparency window.The slow-wave phenomenon is also observed.The measured group delay time goes up and the slow-wave bandwidth decreases,with the decrease of the coupling strength.