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FASOR (laser Physics)
FASOR is an acronym for frequency addition source of optical radiation. The name is used for a certain type of guide star laser deployed at US Air Force Research Laboratory facilities SOR and AMOS. The laser light is produced in a sum-frequency generation process from two solid-state laser sources that operate at different wavelengths. The ''frequencies'' of the sources add directly to a summed frequency. Thus, if the source wavelengths are \lambda_1 and \lambda_2, the resulting wavelength is : \lambda = \left(\frac + \frac \right)^. Application The FASOR was initially used for many laser guide star experiments. These have ranged from mapping the photon return verse wavelength, power, and pointing location in the sky. Two FASORS were used to show the advantages of 'back pumping' or pumping at both D2a and D2b lines. Later a FASOR was used to measure the earth's magnetic field.Kane, T. J., Hillman, P. D., Denman, C. A., Hart, M., Phillip Scott, R., Purucker, M. E., & Potashnik, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starfire Optical Range - Sodium Laser
Starfire or Starfires may refer to: Military * F-94 Starfire, an American fighter aircraft * Starfire Optical Range, a United States Air Force research laboratory Comics * Starfire (Teen Titans) (1980), alien superheroine and member of the Teen Titans, appearing in DC Comics * Starfire (1968), the original name of Red Star, a fictional Russian superhero appearing in DC Comics * Starfire (Star Hunters) (1976), alien swordswoman appearing in DC Comics Books and games * ''Starfire'' (board wargame), a science fiction strategy game by Starfire Design Studio * ''Starfire'' novel series, in the universe of the wargame, primarily written by Steve White and David Weber *''Starfire'', a 1960 novel by Robert Buckner and the basis for the film ''Moon Pilot'' * ''Starfire'' (Paul Preuss novel), a 1988 science fiction novel by Paul Preuss * ''Starfire'', a 1999 science fiction novel by Charles Sheffield * ''Star Fire'', a video arcade game from 1979 Music * The Starfires, a band from Los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Guide Star
A laser guide star is an artificial star image created for use in astronomical adaptive optics systems, which are employed in large telescopes in order to correct atmospheric distortion of light (called '' astronomical seeing''). Adaptive optics (AO) systems require a wavefront reference source of light called a guide star. Natural stars can serve as point sources for this purpose, but sufficiently bright stars are not available in all parts of the sky, which greatly limits the usefulness of natural guide star adaptive optics. Instead, one can create an artificial guide star by shining a laser into the atmosphere. Light from the beam is reflected by components in the upper atmosphere back into the telescope. This star can be positioned anywhere the telescope desires to point, opening up much greater amounts of the sky to adaptive optics. Because the laser beam is deflected by astronomical seeing on the way up, the returning laser light does not move around in the sky a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Force Research Laboratory
The Air Force Research Laboratory (AFRL) is a scientific research organization operated by the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of aerospace warfighting technologies, planning and executing the Air Force science and technology program, and providing warfighting capabilities to United States air, space, and cyberspace forces. It controls the entire Air Force science and technology research budget which was $2.4 billion in 2006. The Laboratory was formed at Wright-Patterson Air Force Base near Dayton, Ohio, on 31 October 1997 as a consolidation of four Air Force laboratory facilities (Wright, Phillips, Rome, and Armstrong) and the Air Force Office of Scientific Research under a unified command. The Laboratory is composed of eight technical directorates, one wing, and the Office of Scientific Research. Each technical directorate emphasizes a particular area of research within the AFRL mission which it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Starfire Optical Range
Starfire Optical Range (SOR - Pronounced as an initialism) is a United States Air Force research laboratory on the Kirtland Air Force Base in Albuquerque, New Mexico. Its primary duty, according to the official website, is to "develop and demonstrate optical wavefront control technologies." The range is a secure lab facility and is a division of the Directed Energy Directorate of the Air Force Research Laboratory. SOR's optical equipment includes a 3.5 meter telescope which is "one of the largest telescopes in the world equipped with adaptive optics designed for satellite tracking" according to the Air Force, a 1.5 meter telescope, and a 1-meter beam director. Purpose The purpose of Starfire is to conduct research to use adaptive optics to remove the effects of scintillation (atmospheric turbulence). Turbulence interferes with laser beam integrity over distances. Lasers are being used for long-distance high-bandwidth communications and accuracy in air-to-air laser connectivi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Force Maui Optical And Supercomputing Observatory
The Air Force Maui Optical and Supercomputing observatory is an Air Force Research Laboratory (AFRL) operating location at Haleakala Observatory on Maui, Hawaii, with a twofold mission (). First, it conducts the research and development mission on the Maui Space Surveillance System (MSSS) at the ''Maui Space Surveillance Complex'' (MSSC). Second, it oversees operation of the Maui High Performance Computing Center (MHPCC). AFRL's research and development mission on Maui was formally called Air Force Maui Optical Station (AMOS); the use of the term AMOS has been widespread throughout the technical community for over thirty years and is still used today at many technical conferences. The main-belt asteroid 8721 AMOS is named after the project. Origins Today's observatory was initiated by the DARPA, Advanced Research Projects Agency (ARPA) in 1961 as the ARPA Midcourse Optical Station (AMOS). It was first proposed by R. Zirkind of ARPA's staff for imaging ballistic missile pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sum-frequency Generation
Sum-frequency generation (SFG) is a second order nonlinear optical process based on the annihilation of two input photons at angular frequencies \omega_1 and \omega_2 while, simultaneously, one photon at frequency \omega_3 is generated. As with any second order \chi^ phenomenon in nonlinear optics, this can only occur under conditions where: the light is interacting with matter, which is asymmetric (for example, surfaces and interfaces); the light has a very high intensity (typically from a pulsed laser). Sum-frequency generation is a "parametric process", meaning that the photons satisfy energy conservation, leaving the matter unchanged: :\hbar\omega_3 = \hbar\omega_1 + \hbar\omega_2 Second-harmonic generation A special case of sum-frequency generation is second-harmonic generation, in which \omega_1=\omega_2. In fact, in experimental physics, this is the most common type of sum-frequency generation. This is because in second-harmonic generation, only one input light beam is re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperfine
In atomic physics, hyperfine structure is defined by small shifts in otherwise degenerate energy levels and the resulting splittings in those energy levels of atoms, molecules, and ions, due to electromagnetic multipole interaction between the nucleus and electron clouds. In atoms, hyperfine structure arises from the energy of the nuclear magnetic dipole moment interacting with the magnetic field generated by the electrons and the energy of the nuclear electric quadrupole moment in the electric field gradient due to the distribution of charge within the atom. Molecular hyperfine structure is generally dominated by these two effects, but also includes the energy associated with the interaction between the magnetic moments associated with different magnetic nuclei in a molecule, as well as between the nuclear magnetic moments and the magnetic field generated by the rotation of the molecule. Hyperfine structure contrasts with '' fine structure'', which results from the interaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fraunhofer Lines
In physics and optics, the Fraunhofer lines are a set of spectral absorption lines named after the German physicist Joseph von Fraunhofer (1787–1826). The lines were originally observed as dark features (absorption lines) in the optical spectrum of the Sun (white light) . Discovery In 1802, the English chemist William Hyde WollastonMelvyn C. UsselmanWilliam Hyde WollastonEncyclopædia Britannica, retrieved 31 March 2013 was the first person to note the appearance of a number of dark features in the solar spectrum. In 1814, Fraunhofer independently rediscovered the lines and began to systematically study and measure the wavelengths where these features are observed. He mapped over 570 lines, designating the principal features (lines) with the letters A through K and weaker lines with other letters. Modern observations of sunlight can detect many thousands of lines. About 45 years later, Kirchhoff and Bunsen noticed that several Fraunhofer lines coincide with characteristic em ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is 23Na. The free metal does not occur in nature, and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been leached by the action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans. Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful sodium compounds, sodium hydroxide (lye) is used in soap manufacture, and sodium chloride (edible salt) is a de-icing agent and a nutrient for animals inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Layer
The sodium layer is a layer of neutral atoms of sodium within Earth's mesosphere. This layer usually lies within an altitude range of above sea level and has a depth of about . The sodium comes from the ablation of meteors. Atmospheric sodium below this layer is normally chemically bound in compounds such as sodium oxide, while the sodium atoms above the layer tend to be ionized. The density varies with season; the average column density (the number of atoms per unit area above any point on the earth's surface) is roughly 4 billion sodium atoms/cm2. For a typical thickness of 5 km this corresponds to volume density of roughly 8000 sodium atoms/cm3. Atoms of sodium in this layer can become excited due to sunlight, solar wind, or other causes. Once excited, these atoms radiate very efficiently around 589 nm, which is in the yellow portion of the spectrum. These radiation bands are known as the '' sodium D lines''. The resulting radiation is one of the sources of air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resonant
Resonance describes the phenomenon of increased amplitude that occurs when the frequency of an applied periodic force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscillating force is applied at a resonant frequency of a dynamic system, the system will oscillate at a higher amplitude than when the same force is applied at other, non-resonant frequencies. Frequencies at which the response amplitude is a relative maximum are also known as resonant frequencies or resonance frequencies of the system. Small periodic forces that are near a resonant frequency of the system have the ability to produce large amplitude oscillations in the system due to the storage of vibrational energy. Resonance phenomena occur with all types of vibrations or waves: there is mechanical resonance, orbital resonance, acoustic resonance, electromagnetic resonance, nuclear magnetic resonance (NMR), electron spin resonance (ESR) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Triborate
Lithium triborate (LiB3O5) or LBO is a non-linear optics crystal. It has a wide transparency range, moderately high nonlinear coupling, high damage threshold and desirable chemical and mechanical properties. This crystal is often used for second harmonic generation (SHG, also known as ''frequency doubling''), for example of Nd:YAG lasers (1064 nm → 532 nm). LBO can be both critically and non-critically phase-matched. In the latter case the crystal has to be heated or cooled depending on the wavelength. Lithium triborate was discovered and developed by Chen Chuangtian and others of the Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences. It has been patented. Chemical properties *Point group: mm2 * Lattice parameters: ''a''=8.4473 Å, ''b''=7.3788 Å, ''c''=5.1395 Å *Mohs hardness: 6 *Transmission range: 0.16 – 2.6 μm * Damage threshold: 25 J/cm2 (1064 nm, 10 ns pulses) *Thermal expansion coefficients: ''x'': 10.8×10−5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
