Related Experiment Video
Updated: May 1, 2026

Using Microwave and Macroscopic Samples of Dielectric Solids to Study the Photonic Properties of Disordered Photonic Bandgap Materials
Published on: September 26, 2014
Size dependence of band-gaps in a one-dimensional plasmonic crystal
Abstract:
The dependence of the plasmonic band gap on size of a one-dimensional plasmonic crystal with a rectangular cross-section has been investigated by cathodoluminescence, using a 200-keV scanning transmission electron microscope. The band edge character at points Γ and X changes in correlation with the corresponding Fourier component of the surface shape. The calculation by the rigorous coupled-wave analysis (RCWA) method reproduces well the observed size dependence of the band edge energies on terrace width and height, though some deviation in magnitude remains. The beam-scan spectral images clearly reveal symmetric and anti-symmetric characters of the standing waves of the band edge modes. The two modes at the band edges are different in the surface plasmon Polariton (SPP)-light conversion efficiency and exchange their energy positions by changing terrace width.
Related Concept Videos
Band Theory
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Energy Bands in Solids
Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states...
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
Semiconductors
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
X-ray Crystallography
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...

