Quasioptics concerns the propagation of
electromagnetic radiation where the
wavelength is comparable to the size of the optical components (e.g. lenses, mirrors, and apertures) and hence
diffraction
Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a s ...
effects may become significant. It commonly describes the propagation of
Gaussian beams where the
beam width is comparable to the wavelength. This is in contrast to
geometrical optics, where the wavelength is small compared to the relevant length scales. Quasioptics is so named because it represents an intermediate regime between conventional
optics and
electronics, and is often relevant to the description of signals in the
far-infrared or
terahertz
Terahertz or THz may refer to:
* Terahertz (unit), a unit of frequency, defined as one trillion (1012) cycles per second or 1012 hertz
* Terahertz radiation, electromagnetic waves within the ITU-designated band of frequencies from 0.3 to 3 terahe ...
region of the electromagnetic spectrum. It represents a simplified version of the more rigorous treatment of
physical optics
In physics, physical optics, or wave optics, is the branch of optics that studies interference, diffraction, polarization, and other phenomena for which the ray approximation of geometric optics is not valid. This usage tends not to include effec ...
. Quasi-optical systems may also operate at lower frequencies such as
millimeter wave,
microwave, and even lower.
See also
*
Optoelectronics
References
Optics
Terahertz technology
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