Related Experiment Video
Updated: Jun 21, 2026
09:38
Fabrication Procedures and Birefringence Measurements for Designing Magnetically Responsive Lanthanide Ion Chelating Phospholipid Assemblies
Published on: January 3, 2018
Bi-layer cross chiral structure with strong optical activity and negative refractive index
Jianfeng Dong1, Jiangfeng Zhou, Thomas Koschny
1Institute of Optical Fiber Communication and Network Technology, Ningbo University, Ningbo, Zhejiang 315211, China. dongjianfeng@nbu.edu.cn
Optics Express
|August 6, 2009
Summary
Researchers investigated twisted silver crosses separated by a dielectric layer. They discovered strong polarization rotation, circular dichroism, and negative refractive index at infrared wavelengths.
Area of Science:
- Metamaterials
- Plasmonics
- Nanophotonics
Background:
- Metallic nanostructures exhibit unique optical properties due to surface plasmon resonances.
- Tailoring the geometry and arrangement of nanoparticles can control light-matter interactions.
- Periodic structures offer enhanced optical responses and potential for wave manipulation.
Purpose of the Study:
- To investigate the optical properties of periodic pairs of mutually twisted metallic (silver) crosses.
- To explore the potential of these structures for applications in infrared communication.
- To determine if negative permeability and negative refractive index can be achieved.
Main Methods:
- Numerical simulation of electromagnetic wave interaction with periodic metallic nanostructures.
- Modeling of silver crosses with specific geometric parameters and dielectric separation.
- Analysis of polarization rotation, circular dichroism, permeability, and refractive index spectra.
Main Results:
- Exceptionally strong polarization rotation observed.
- Significant circular dichroism demonstrated.
- Negative permeability and negative refractive index achieved at infrared communication wavelengths (1.55 microm).
Conclusions:
- Periodic pairs of twisted silver crosses exhibit remarkable optical properties.
- These metamaterials show potential for advanced optical devices operating at infrared frequencies.
- The study confirms the feasibility of achieving negative optical parameters in plasmonic nanostructures.
Related Concept Videos
02:24Properties of Enantiomers and Optical Activity
It is essential to understand the difference between chiral and achiral interactions and the implications thereof in optical activity and their applications. Just as our feet, which are chiral, interact uniquely with chiral objects, such as a pair of shoes, but identically with achiral socks, enantiomers of a molecule exhibit different properties only when they interact with other chiral media. An example of a significant implication from this facet is the phenomenon known as optical activity,...
02:25Chirality
Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
02:05Prochirality
The concept of prochirality leads to the nomenclature of the individual faces of a molecule and plays a crucial role in the enantioselective reaction. It is a concept where two or more achiral molecules react to produce chiral products. A typical process is the reaction of an achiral ketone to generate a chiral alcohol. Here, the achiral reactant reacts with an achiral reducing agent, sodium borohydride, to generate an equimolar mixture of the chiral enantiomers of the product. For example, an...
02:25Molecules with Multiple Chiral Centers
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
02:52Stereoisomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
02:30Chirality in Nature
Chirality is the most intriguing yet essential facet of nature, governing life’s biochemical processes and precision. It can be observed from a snail shell pattern in a macroscopic world to an amino acid, the minutest building block of life. Most of the snails around the world have right-coiled shells because of the intrinsic chirality in their genes. All the amino acids present in the human body exist in an enantiomerically pure state, except for glycine - the sole achiral amino acid. The...