Gaussian optics is a technique in
geometrical optics that describes the behaviour of light rays in optical systems by using the
paraxial approximation, in which only rays which make small angles with the
optical axis
An optical axis is a line along which there is some degree of rotational symmetry in an optical system such as a camera lens, microscope or telescopic sight.
The optical axis is an imaginary line that defines the path along which light pro ...
of the system are considered. In this approximation, trigonometric functions can be expressed as linear functions of the angles. Gaussian optics applies to systems in which all the optical surfaces are either flat or are portions of a
sphere
A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the c ...
. In this case, simple explicit formulae can be given for parameters of an imaging system such as
focal length
The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative foc ...
,
magnification
Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a calculated number also called "magnification". When this number is less than one, it refers to a reduction in si ...
and brightness, in terms of the geometrical shapes and material properties of the constituent elements.
Gaussian optics is named after
mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems.
Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change.
History
On ...
and
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.
Physicists generally are interested in the root or ultimate cau ...
Carl Friedrich Gauss, who showed that an optical system can be characterized by a series of
cardinal points, which allow one to calculate its
optical properties The optical properties of a material define how it interacts with light. The optical properties of matter are studied in optical physics, a subfield of optics. The optical properties of matter include:
* Refractive index
*Dispersion
* Transmittan ...
.
[W.J. Smith]
''Modern Optical Engineering''
2007, McGraw-Hill, p. 22.
References
Geometrical optics
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