Metamaterials are a novel class of man-made materials with engineered qualities that surpass those found in nature.
Unlike most substances, whose behavior is determined by chemical makeup, metamaterials derive their exceptional electromagnetic, optical, and mechanical properties from the geometry and organization of their internal structures.
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These structures, arranged into periodic, nanoscale patterns, interact with waves of light, sound, or stress in ways determined by their spatial arrangement as well as the basic atomic characteristics of their bulk materials.
Metamaterials can be made of a variety of materials, including metals (such as gold, silver, and aluminum), semiconductors, dielectrics, and polymers. They can enable scientists to precisely adjust their reactions ("tune") across the UV, visible, and infrared spectral ranges.
When the repeating structural parts are smaller than the wavelength of the interacting radiation, these materials exhibit unusual properties, such as negative refractive indices, reverse Doppler shifts, and even cloaking abilities.
Metamaterials' remarkable tunable qualities make them extremely promising for next-generation technologies such as ultra-compact optical components, super-resolution imaging, radar evasion systems, and improved sensors. Their advancements continue to push the boundaries of material science and applied optics.
Circular dichroism (CD) spectroscopy is a powerful analytical technique used to investigate the chiroptical properties of molecules, specifically how they interact differently with left- and right-handed circularly polarized light.
This variation in absorption, known as circular dichroism, occurs when a molecule or material is optically active, typically due to its chirality. In practice, CD spectroscopy analyzes the differential absorption (ΔA) of left- and right-circularly polarized light as a function of wavelength.
The spectrum resulting from this technique reveals important details regarding molecule conformation, secondary structure, and electronic transitions. This information has made CD spectroscopy an effective tool for investigating chiral and asymmetric systems at both the molecular and nanoscale levels in materials science and nanotechnology.
Beyond its conventional use in investigating biomolecules, such as proteins and nucleic acids, CD spectroscopy is now routinely used to characterize chiral metamaterials, plasmonic nanostructures, and other designed optical materials with chirality.
Because of their nanoscale geometry, these advanced materials often exhibit considerable differential absorption of left- and right-circularly polarized light.
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CD microspectroscopy combines microscopy's great spatial resolution with the strength of CD spectroscopy. A 2030PV PRO™ integrated with CD microspectroscopy provides spatially resolved insights into the chiroptical properties of metamaterials and metasurfaces.
These designed materials frequently use nanoscale or microscale chiral geometries, rather than molecular chirality, to generate novel optical phenomena such as polarization rotation, circular birefringence, and asymmetric transmission.
CD microspectroscopy enables scientists to precisely detect the differential absorption of left- and right-circularly polarized light at specific locations on a metamaterial sample.
3 micron solid gyroid using reflectance CD microspectroscopy. Image Credit: CRAIC Technologies
CD microspectra of a 3 µm solid gyroid. Image Credit: CRAIC Technologies
By mapping these polarization-dependent optical responses, researchers can visualize local variations in chirality, detect fabrication flaws, and correlate geometric asymmetries with optical performance.
This information is critical for improving the design and production of chiral metamaterials, plasmonic arrays, and dielectric metastructures used for advanced optical functionalities such as polarization control, enantioselective sensing, and optical data encoding.
CD microspectroscopy is a powerful bridge between material design, nanofabrication, and performance evaluation, enabling the optimization of next-generation metamaterials and photonic devices that use controlled chirality for novel optical applications.
CRAIC Technologies' 2030PV PRO™ UV-visible-NIR microspectrophotometer demonstrates these capabilities. The 2030PV PRO™ is designed for precise spectral and imaging research. The 2030PV PRO™ enables scientists to directly analyze the optical performance of microscopic features, providing valuable data for the development of materials.
Its ability to perform transmission, reflectance, and absorbance measurements all in one instrument simplifies research procedures and leads to improved repeatability.
The 2030PV PRO™ is a valuable tool for materials scientists, physicists, and optical engineers working on metamaterial and metasurface technologies. It connects nanoscale fabrication with macroscopic optical innovation, facilitating the development of new engineered materials.
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This information has been sourced, reviewed, and adapted from materials provided by CRAIC Technologies.
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