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Filling Factor
Filling factor, ~F,~ is a quantity measuring the efficiency of absorption of pump in the core of a double-clad fiber.D. Kouznetsov, J. V. Moloney. Highly efficient, high gain, short wavelength and power scalable incoherent diode slab-pumped fiber laser amplifier. IEEE Journal of Quantum Electronics, v.39, No.11, p.1452-1461 (2003) Definition The efficiency of absorption of pumping energy in the fiber is an important parameter of a double-clad fiber laser. In many cases this efficiency can be approximated with :1- \exp\left( - F \frac\alpha L \right) , where :~S~ is the cross-sectional area of the cladding :~r~ is the radius of the core (which is taken to be circular) :~\alpha~ is the absorption coefficient of pump light in the core :~L~ is the length of the double-clad fiber, and :~F~ is a dimensionless adjusting parameter, which is sometimes called the "filling factor"; ~0 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double-clad Fiber
Double-clad fiber (DCF) is a class of optical fiber with a structure consisting of three layers of optical material instead of the usual two. The inner-most layer is called the ''core''. It is surrounded by the ''inner cladding'', which is surrounded by the ''outer cladding''. The three layers are made of materials with different refractive indices. There are two different kinds of double-clad fibers. The first was developed early in optical fiber history with the purpose of engineering the dispersion of optical fibers. In these fibers, the core carries the majority of the light, and the inner and outer cladding alter the waveguide dispersion of the core-guided signal. The second kind of fiber was developed in the late 1980s for use with high power fiber amplifiers and fiber lasers. In these fibers, the core is doped with active dopant material; it both guides and amplifies the signal light. The inner cladding and core together guide the pump light, which provides the energy nee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE Journal Of Quantum Electronics
The ''IEEE Journal of Quantum Electronics'' is a peer-reviewed scientific journal covering optical, electrical, and electronics engineering, and some applied aspects of lasers, physical optics, and quantum electronics. It is published by the IEEE Photonics Society and was established in 1965. The editor-in-chief is Hon Ki Tsang (The Chinese University of Hong Kong). According to the ''Journal Citation Reports'', the journal has a 2020 impact factor of 2.318. Abstracting and indexing The journal is abstracted and indexed in: * Science Citation Index * Current Contents ''Current Contents'' is a rapid alerting service database from Clarivate Analytics, formerly the Institute for Scientific Information and Thomson Reuters. It is published online and in several different printed subject sections. History ''C .../Physical, Chemical & Earth Sciences * Current Contents/Engineering, Computing & Technology See also * '' IEEE Journal on Selected Topics in Quantum Electronics'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absorption Coefficient
The linear attenuation coefficient, attenuation coefficient, or narrow-beam attenuation coefficient characterizes how easily a volume of material can be penetrated by a beam of light, sound, particles, or other energy or matter. A coefficient value that is large represents a beam becoming 'attenuated' as it passes through a given medium, while a small value represents that the medium had little effect on loss. The SI unit of attenuation coefficient is the reciprocal metre (m−1). Extinction coefficient is another term for this quantity, often used in meteorology and climatology. Most commonly, the quantity measures the exponential decay of intensity, that is, the value of downward ''e''-folding distance of the original intensity as the energy of the intensity passes through a unit (''e.g.'' one meter) thickness of material, so that an attenuation coefficient of 1 m−1 means that after passing through 1 metre, the radiation will be reduced by a factor of '' e'', and for material ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimensionless Number
A dimensionless quantity (also known as a bare quantity, pure quantity, or scalar quantity as well as quantity of dimension one) is a quantity to which no physical dimension is assigned, with a corresponding SI unit of measurement of one (or 1), ISBN 978-92-822-2272-0. which is not explicitly shown. Dimensionless quantities are widely used in many fields, such as mathematics, physics, chemistry, engineering, and economics. Dimensionless quantities are distinct from quantities that have associated dimensions, such as time (measured in seconds). Dimensionless units are dimensionless values that serve as units of measurement for expressing other quantities, such as radians (rad) or steradians (sr) for plane angles and solid angles, respectively. For example, optical extent is defined as having units of metres multiplied by steradians. History Quantities having dimension one, ''dimensionless quantities'', regularly occur in sciences, and are formally treated within the field o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brightness
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. The perception is not linear to luminance, and relies on the context of the viewing environment (for example, see White's illusion). Brightness is a subjective sensation of an object being observed and one of the color appearance parameters of many color appearance models, typically denoted as Q. Brightness refers to how much light ''appears to shine'' from something. This is a different perception than lightness, which is how light something appears ''compared to'' a similarly lit white object. The adjective '' bright'' derives from an Old English '' beorht'' with the same meaning via metathesis giving Middle English ''briht''. The word is from a Common Germanic ', ultimately from a PIE root with a closely related meaning, *' "white, bright". "Brightness" was formerly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Scaling
Power scaling of a laser is increasing its output power without changing the geometry, shape, or principle of operation. Power scalability is considered an important advantage in a laser design. this means it can increase power without changing outside features! Usually, power scaling requires a more powerful pump source, stronger cooling, and an increase in size. It may also require reduction of the background loss in the laser resonator and, in particular, in the gain medium. MOPA The most popular way of achieving power scalability is the "MOPA" (Master Oscillator Power Amplifier) approach. The master oscillator produces a highly coherent beam, and an optical amplifier is used to increase the power of the beam while preserving its main properties. The master oscillator has no need to be powerful, and has no need to operate at high efficiency because the efficiency is determined mainly by the power amplifier. The combination of several laser amplifiers seeded by a common master o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stimulated Scattering
"Stimulated" (stylized as "$timulated") is a song by American rapper Tyga, and the fifth single from his mixtape '' Fuk Wat They Talkin Bout'' (2015). It was produced by Crakwav and uses a sample of " Children" by Robert Miles. The song is a response to the controversy and criticism surrounding Tyga's relationship with media personality Kylie Jenner. Background and composition In 2014, Tyga and Kylie Jenner began a romantic relationship, which Tyga publicly confirmed when Jenner turned 18 (the legal age of consent in California) in 2015. The news sparked controversy due to their age differences. Tyga responded to the negative publicity with the song, in which he dismisses the criticism of the relationship and describes his sexual exploits with Jenner, rapping over a sample of "Children". Reception The song was widely criticized by music critics and the general public alike. It has been viewed as glorification of statutory rape. Many particularly disapproved of the line "They say s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Amplifier
An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Optical amplifiers are important in optical communication and laser physics. They are used as optical repeaters in the long distance fiberoptic cables which carry much of the world's telecommunication links. There are several different physical mechanisms that can be used to amplify a light signal, which correspond to the major types of optical amplifiers. In doped fiber amplifiers and bulk lasers, stimulated emission in the amplifier's gain medium causes amplification of incoming light. In semiconductor optical amplifiers (SOAs), electron- hole recombination occurs. In Raman amplifiers, Raman scattering of incoming light with phonons in the lattice of the gain medium produces photons coherent with the inco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
