The strong chiroptical effect is highly desirable and has a wide range of applications in biosensing, chiral catalysis,polarization tuning, and chiral photo detection. In this work, we find a simple method to enhance ...The strong chiroptical effect is highly desirable and has a wide range of applications in biosensing, chiral catalysis,polarization tuning, and chiral photo detection. In this work, we find a simple method to enhance the reflection circular dichroism(CDR) by placing the planar anisotropic chiral metamaterials(i.e., Z-shaped PACMs) on the interface of two media(i.e., Z-PCMI) with a large refractive index difference. The maximum reflection CDR from the complex system can reach about 0.840 when the refractive index is set as ntop = 4.0 and nbottom = 1.49, which is approximately three times larger than that of placing the Z-shaped PACMs directly on the substrate(i.e., Z-PCMS). While the minimum reflection CDR is 0.157 when the refractive index is set as ntop = 1.0 and nbottom = 1.49. So we can get a large available range of reflection CDR from -0.840 to -0.157. Meanwhile, the transmission CDT remains unchanged with the refractive index ntop increment. Our in-depth research indicates that the large reflection CDR is derived from the difference of non-conversion components of the planar anisotropic chiral metamaterials’ reflection matrices. In short, we provide a simple and practical method to enhance the chiroptical effect by changing the refractive index difference between two media without having to design a complex chiral structure.展开更多
High performance optical diode-like devices are highly desired in future practical nano-photonic devices with strong directional selectivity.We demonstrate a kind of giant broadband reciprocity optical diode-like devi...High performance optical diode-like devices are highly desired in future practical nano-photonic devices with strong directional selectivity.We demonstrate a kind of giant broadband reciprocity optical diode-like devices by simultaneously using the directional Mie scattering effect and the asymmetric grating diffraction effect.The maximum asymmetric subtraction and the asymmetric transmission ratio can reach nearly 100%and 40dB at specified wavelength,respectively.In a wide waveband from 500nm to 800nm,the asymmetric subtraction and the ratio keep larger than 80%and 3.5 dB,respectively,even under oblique incidence.To the best of our knowledge,this is the best one-way-transmission effect observed in the reciprocity optical diode-like devices.In addition,we further demonstrate that this one-way-transmission effect can bring an effective absorption enhancement on gold films.The giant,broadband and angle-insensitive one-way-transmission effect demonstrated here is far beyond the well-known anti-reflection effect in the light-trapping devices and will bring new design philosophy for nano-photonic devices.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 11604227).
文摘The strong chiroptical effect is highly desirable and has a wide range of applications in biosensing, chiral catalysis,polarization tuning, and chiral photo detection. In this work, we find a simple method to enhance the reflection circular dichroism(CDR) by placing the planar anisotropic chiral metamaterials(i.e., Z-shaped PACMs) on the interface of two media(i.e., Z-PCMI) with a large refractive index difference. The maximum reflection CDR from the complex system can reach about 0.840 when the refractive index is set as ntop = 4.0 and nbottom = 1.49, which is approximately three times larger than that of placing the Z-shaped PACMs directly on the substrate(i.e., Z-PCMS). While the minimum reflection CDR is 0.157 when the refractive index is set as ntop = 1.0 and nbottom = 1.49. So we can get a large available range of reflection CDR from -0.840 to -0.157. Meanwhile, the transmission CDT remains unchanged with the refractive index ntop increment. Our in-depth research indicates that the large reflection CDR is derived from the difference of non-conversion components of the planar anisotropic chiral metamaterials’ reflection matrices. In short, we provide a simple and practical method to enhance the chiroptical effect by changing the refractive index difference between two media without having to design a complex chiral structure.
基金Supported by the National Natural Science Foundation of China under Grant No.11604227。
文摘High performance optical diode-like devices are highly desired in future practical nano-photonic devices with strong directional selectivity.We demonstrate a kind of giant broadband reciprocity optical diode-like devices by simultaneously using the directional Mie scattering effect and the asymmetric grating diffraction effect.The maximum asymmetric subtraction and the asymmetric transmission ratio can reach nearly 100%and 40dB at specified wavelength,respectively.In a wide waveband from 500nm to 800nm,the asymmetric subtraction and the ratio keep larger than 80%and 3.5 dB,respectively,even under oblique incidence.To the best of our knowledge,this is the best one-way-transmission effect observed in the reciprocity optical diode-like devices.In addition,we further demonstrate that this one-way-transmission effect can bring an effective absorption enhancement on gold films.The giant,broadband and angle-insensitive one-way-transmission effect demonstrated here is far beyond the well-known anti-reflection effect in the light-trapping devices and will bring new design philosophy for nano-photonic devices.
