Optics is the branch of physics that describes the
behavior and properties of light and the interaction of light with matter.
Optics explained and characterized by optical phenomena. The word comes from
the Latin optics ὀπτική, meaning the display.
The field of optics usually describes the properties
of visible light, infrared and ultraviolet light, but as the light is an
electromagnetic wave, a similar phenomenon also occurs in the X-rays,
microwaves, radio waves, and other forms of radiation elektromagnetikdan
similar symptoms as well as
in the charge particle beam ( charged beam). Optics
can generally be considered as part darikeelektromagnetan. Some optical
phenomena depend on the quantum nature of light related to several fields of
quantum optics hinggamekanika. In practice, most of the optical phenomena can
be calculated using daricahaya electromagnetic properties, as described by
Maxwell's equations.
Field of optics have an identity, community, and
conferences. Aspects of the field are often called optical science or optical
physics. Applied optical sciences are often called optical engineering. Applications
of optical engineering related specifically to illumination systems
(illumination) is called illumination engineering. Each discipline tends to be
slightly different in application, technical skills, focus, and professional
affiliations. More recent innovations in optical engineering are often
categorized as photonics or optoelectronics. The boundaries between these
fields and the "optics" are not clear, and the terms are used
differently in different parts of the world and in various industrial fields.
Due to the wide application of the science of
"light" for real-world applications, the science of optics and
optical engineering tend to be highly interdisciplinary. Science of optics is
part of a range of related disciplines including electrical engineering,
physics, psychology, medicine (especially optalmologidan optometry), and
others. In addition, the most complete optical behavior, as described in
physics, is unnecessarily complicated for most problems, so a simple model can
be used. Simple model is sufficient to explain most of the behavior of optical
phenomena and ignore irrelevant and / or not detected on a system.
In the free space at the speed of a traveling wave c
= 3 × 10^8 meters / second. When entering a particular medium (dielectric or
nonconducting) wave with a velocity v, which is characteristic of the material
and less than besarnyakecepatan light itself (c). Comparison of the speed of
light in a vacuum to the speed of light in a medium is the refractive index of
the material n as follows: n = c / v
Classical optics
Before quantum optics became important, asarnya
consists of classical electromagnetic applications and high-frequency approach
to light. Classical optics is divided into two main branches: geometrical
optics and physical optics.
Geometric optics, or ray optics, describes light
propagation in the form of "light". Beam deflected at the interface
between two different media, and can be curved in a medium in which the
index-refraksinya a function of position. "Ray" in geometric optics
is an abstract object, or "instrument", which is parallel to the
optical wavefront darigelombang actually. Geometrical optics provides rules for
the deployment of these rays through the optical system, which shows how the
actual wavefront will spread. This is a significant simplification of optics,
and fails to take into account many important optical effects such as
diffraction and polarization. But this is a good approach, if the wavelength of
light is very small compared to the size of the structures that interact with
it. Geometric optics can be used to describe the geometric aspects of the
depiction of light (imaging), including optical aberration.
Geometrical optics is often simplified further by
paraksial approach, or "small angle approach." Mathematical behavior
then becomes linear, allowing optical components and systems described in terms
of a simple matrix. This leads to the Gauss optical techniques and ray tracing
paraksial, used untui first order optical systems, such as estimating the position
and magnification of the image and the object. Propagation is an extension of
the Gaussian beam optics paraksial provide more accurate models of coherent
radiation like laser beams. While still using paraksial approach, this
technique takes into account diffraction, and allows calculation of the laser
beam magnification comparable to the distance, and the minimum size that can be
focused beam. Gaussian beam propagation bridge the gap between geometric and
physical optics.
Physical optics or wave optics form the Huygens
principle and modeling the propagation of complex wavefronts through optical
systems, including amplitude and phase of the wave. This technique, which is
usually applied numerically on a computer, it can calculate the effects of
diffraction, interference, polarization, and other complex effects. But that
the approximation is used, so it is not completely model the electromagnetic
wave theory of light propagation. Complete model is much more computationally
demanding, but can be used to solve small problems that require more accurate
solution.
source : http://id.wikipedia.org/wiki/Optika
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