Thermal blooming or thermal lensing occurs when high-energy
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word ''laser'' originated as an acronym for light amplification by stimulated emission of radi ...
beams propagate through a
medium
Medium may refer to:
Aircraft
*Medium bomber, a class of warplane
* Tecma Medium, a French hang glider design Arts, entertainment, and media Films
* ''The Medium'' (1921 film), a German silent film
* ''The Medium'' (1951 film), a film vers ...
.
It is the result of
nonlinear
In mathematics and science, a nonlinear system (or a non-linear system) is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathe ...
interactions that occur when the medium (e.g. air or glass) is heated by
absorbing a fraction of the radiation, causing a "thermal lens" to form, with a
dioptric power related to the intensity of the laser, among other factors. The amount of
energy
Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and l ...
absorbed is a function of the laser
wavelength
In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats.
In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...
. The term "thermal blooming" is typically used when the medium is air, and can describe any type of self-induced "thermal distortion" of laser radiation. The term "thermal lensing" is typically used when describing thermal effects in the laser's
gain medium
The active laser medium (also called a gain medium or lasing medium) is the source of optical gain within a laser. The gain results from the stimulated emission of photons through electronic or molecular transitions to a lower energy state from ...
itself.
See also
*
Optical Kerr effect
The Kerr effect, also called the quadratic electro-optic (QEO) effect, is a change in the refractive index of a material in response to an applied electric field. The Kerr effect is distinct from the Pockels effect in that the induced index chang ...
References
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Laser science
Nonlinear optics
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