This indeterminacy in wavelength in solids is important in the analysis of wave phenomena such as [[energy bands]] and [[phonons|lattice vibrations]]. It is mathematically equivalent to the [[aliasing]] of a signal that is [[sampling (signal processing)|sampled]] at discrete intervals.
==Subwavelength==
The term ''subwavelength'' is used to describe an object having one or more dimensions smaller than the length of the wave with which the object interacts. For example, the term ''[[subwavelength-diameter optical fibre]]'' means an [[optical fibre]] whose diameter is less than the wavelength of light propagating through it.
A subwavelength particle is a particle smaller than the wavelength of light with which it interacts (see [[Rayleigh scattering]]). Subwavelength [[aperture]]s are holes smaller than the wavelength of light propagating through them. Such structures have applications in [[extraordinary optical transmission]], and [[zero-mode waveguide]]s, among other areas of [[photonics]].
''Subwavelength'' may also refer to a phenomenon involving subwavelength objects; for example, [[subwavelength imaging]].
