Light confined below the wavelength
Modes, Maxwell equations, evanescent waves and optical confinement.
Explore the 8 concepts
Concept 01Diffraction and the nanoscaleA propagating far-field wave cannot freely resolve arbitrary subwavelength detail.Concept 02Maxwell equations in matterNanophotonics starts with electromagnetic boundary-value problems in structured media.Concept 03Waveguides and effective indexGuided modes propagate with phase constants determined by geometry and materials.Concept 04Evanescent fields and near-field opticsEvanescent waves carry subwavelength structure but decay away from an interface.Concept 05Optical mode volumeSmall mode volumes concentrate the electric field per photon.Concept 06Quality factor and photon lifetimeThe quality factor quantifies stored optical energy relative to energy loss.Concept 07Dispersion and group velocityWaveguide dispersion controls pulse propagation and light–matter interaction time.Concept 08Photonic crystals and band gapsPeriodic refractive-index structures reshape allowed electromagnetic modes.