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Multiple-prism Grating Laser Oscillator
Multiple-prism grating laser oscillators, F. J. Duarte, Narrow-linewidth pulsed dye laser oscillators, in ''Dye Laser Principles'' (Academic, New York, 1990) Chapter 4. or MPG laser oscillators, use multiple-prism beam expansion to illuminate a diffraction grating mounted either in Littrow configuration or grazing-incidence configuration. Originally, these narrow-linewidth tunable dispersive oscillators were introduced as multiple-prism Littrow (MPL) grating oscillators, or hybrid multiple-prism near-grazing-incidence (HMPGI) grating cavities, in organic dye lasers. However, these designs were quickly adopted for other types of lasers such as gas lasers, diode lasers, and more recently fiber lasers. Excitation Multiple-prism grating laser oscillators can be excited either electrically, as in the case of gas lasers and semiconductor lasers, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beam Expander
Beam expanders are optical devices that take a collimated beam of light and expand its width (or, used in reverse, reduce its width). In laser physics they are used either as intracavity or extracavity elements. They can be telescopic in nature or prismatic. Generally prismatic beam expanders use several prisms and are known as multiple-prism beam expanders. Telescopic beam expanders include refracting and reflective telescopes. A refracting telescope commonly used is the Galilean telescope which can function as a simple beam expander for collimated light. The main advantage of the Galilean design is that it never focuses a collimated beam to a point, so effects associated with high power density such as dielectric breakdown are more avoidable than with focusing designs such as the Keplerian telescope. When used as intracavity beam expanders, in laser resonators, these telescopes provide two-dimensional beam expansion in the 20–50 range. In tunable laser resonators i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coherent Anti-Stokes Raman Spectroscopy
Coherent anti-Stokes Raman spectroscopy, also called Coherent anti-Stokes Raman scattering spectroscopy (CARS), is a form of spectroscopy used primarily in chemistry, physics and related fields. It is sensitive to the same vibrational signatures of molecules as seen in Raman spectroscopy, typically the nuclear vibrations of chemical bonds. Unlike Raman spectroscopy, CARS employs multiple photons to address the molecular vibrations, and produces a Coherence (physics), coherent signal. As a result, CARS is orders of magnitude stronger than spontaneous Raman emission. CARS is a third-order nonlinear optics, nonlinear optical process involving three laser beams: a pump beam of frequency ωp, a George Gabriel Stokes, Stokes beam of frequency ωS and a probe beam at frequency ωpr. These beams interact with the sample and generate a coherent optical signal at the Stokes line, anti-Stokes frequency (ωpr+ωp-ωS). The latter is resonantly enhanced when the frequency difference between the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Optics
Quantum optics is a branch of atomic, molecular, and optical physics and quantum chemistry that studies the behavior of photons (individual quanta of light). It includes the study of the particle-like properties of photons and their interaction with, for instance, atoms and molecules. Photons have been used to test many of the counter-intuitive predictions of quantum mechanics, such as entanglement and teleportation, and are a useful resource for quantum information processing. History Light propagating in a restricted volume of space has its energy and momentum quantized according to an integer number of particles known as photons. Quantum optics studies the nature and effects of light as quantized photons. The first major development leading to that understanding was the correct modeling of the blackbody radiation spectrum by Max Planck in 1899 under the hypothesis of light being emitted in discrete units of energy. The photoelectric effect was further evidence of thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunable Laser
A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. While all active laser medium, laser gain media allow small shifts in output wavelength, only a few types of lasers allow continuous tuning over a significant wavelength range. There are many types and categories of tunable lasers. They exist in the gas, liquid, and solid states. Among the types of tunable lasers are excimer lasers, gas lasers (such as CO2 laser, CO2 and helium–neon laser, He-Ne lasers), dye lasers (liquid and solid state), transition-metal solid-state lasers, semiconductor crystal and diode lasers, and free electron laser, free-electron lasers. Tunable lasers find applications in spectroscopy, photochemistry, atomic vapor laser isotope separation, and optical communications. Types of tunability Single line tuning No real laser is truly monochromatic#In physics, monochromatic; all lasers can emit light over some range of frequencies, known as the linewidth of the las ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarization Rotator
A polarization rotator is an optical device that rotates the polarization axis of a linearly polarized light beam by an angle of choice. Such devices can be based on the Faraday effect, on birefringence, or on total internal reflection. F. J. Duarte''Tunable Laser Optics'' 2nd edition (CRC, New York, 2015). Chapter 5. Rotators of linearly polarized light have found widespread applications in modern optics since laser beams tend to be linearly polarized and it is often necessary to rotate the original polarization to its orthogonal alternative. Faraday rotators A Faraday rotator consists of an optical material in a magnetic field. When light propagates in the material, interaction with the magnetic field causes left- and right-handed circularly polarized waves to propagate with slightly different phase velocities. Since a linearly-polarized wave can be described as a superposition of left- and right-handed circularly polarized waves, the difference in phase velocity causes th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple-prism Dispersion Theory
The first description of multiple-prism arrays, and multiple-prism dispersion, was given by Isaac Newton in his book '' Opticks,'' also introducing prisms as beam expanders. Prism pair expanders were introduced by David Brewster in 1813. A modern mathematical description of the single-prism dispersion was given by Max Born and Emil Wolf in 1959.M. Born and E. Wolf, '' Principles of Optics'', 7th Ed. (Cambridge University, Cambridge, 1999). The generalized multiple-prism dispersion theory was introduced by F. J. Duarte and PiperF. J. Duarte and J. A. Piper, "Dispersion theory of multiple-prism beam expanders for pulsed dye lasers", ''Opt. Commun.'' 43, 303–307 (1982).F. J. Duarte and J. A. Piper, "Generalized prism dispersion theory", ''Am. J. Phys.'' 51, 1132–1134 (1982). in 1982. Generalized multiple-prism dispersion equations The generalized mathematical description of multiple-prism dispersion, as a function of the angle of incidence, prism geometry, prism refractive i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Linewidth
Laser linewidth is the spectral linewidth of a laser beam. Two of the most distinctive characteristics of laser emission are spatial coherence and spectral coherence. While spatial coherence is related to the beam divergence of the laser, spectral coherence is evaluated by measuring the linewidth of laser radiation. Theory History: First derivation of the laser linewidth The first human-made coherent light source was a maser. The acronym MASER stands for "Microwave Amplification by Stimulated Emission of Radiation". More precisely, it was the ammonia maser operating at 12.5 mm wavelength that was demonstrated by Gordon, Zeiger, and Townes in 1954. One year later the same authors derived theoretically the linewidth of their device by making the reasonable approximations that their ammonia maser Notably, their derivation was entirely semi-classical, describing the ammonia molecules as quantum emitters and assuming classical electromagnetic fields (but no quantized f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid State Dye Lasers
Organic solid-state narrow-linewidth tunable dye laser oscillator A solid-state dye laser (SSDL) is a solid-state lasers in which the gain medium is a laser dye-doped organic matrix such as poly(methyl methacrylate) (PMMA), rather than a liquid solution of the dye. These lasers are also referred to as ''solid-state organic lasers'' and ''solid-state dye-doped polymer lasers''. SSDLs were introduced in 1967 by Soffer and McFarland. Organic gain media In the 1990s, new forms of improved PMMA, such as modified PMMA, with high optical quality characteristics were introduced. Gain media research for SSDL has been rather active in the 21st century, and various new dye-doped solid-state organic matrices have been discovered. Notable among these new gain media are organic-inorganic dye-doped polymer-nanoparticle composites. An additional form of organic-inorganic dye-doped solid-state laser gain media are the ORMOSILs. High performance solid-state dye laser oscillators This im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dye Lasers
A dye laser is a laser that uses an organic dye as the lasing medium, usually as a liquid solution. Compared to gases and most solid state lasing media, a dye can usually be used for a much wider range of wavelengths, often spanning 50 to 100 nanometers or more. The wide bandwidth makes them particularly suitable for tunable lasers and pulsed lasers. The dye rhodamine 6G, for example, can be tuned from 635 nm (orangish-red) to 560 nm (greenish-yellow), and produce pulses as short as 16 femtoseconds. Moreover, the dye can be replaced by another type in order to generate an even broader range of wavelengths with the same laser, from the near-infrared to the near-ultraviolet, although this usually requires replacing other optical components in the laser as well, such as dielectric mirrors or pump lasers. Dye lasers were independently discovered by P. P. Sorokin and F. P. Schäfer (and colleagues) in 1966. In addition to the usual liquid state, dye lasers are also avail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Vapor Laser Isotope Separation
Atomic vapor laser isotope separation, or AVLIS, is a method by which specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions. A similar technology, using molecules instead of atoms, is molecular laser isotope separation (MLIS). Natural uranium consists of a large mass of 238U and a much smaller mass of fissile 235U. Traditionally, the 235U is separated from the mass by dissolving it in acid to produce uranium hexafluoride and then using gas centrifuges to separate the isotopes. Each trip through the centrifuge "enriches" the amount of 235U and leaves behind depleted uranium. In contrast, AVLIS produces much higher enrichment in a single step without the need to mix it with acid. The technology could, in principle, also be used for isotope separation of other elements, which is uneconomic outside specialist applications with current non-laser-based technologies for most elements. As the process does not require the fee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy
Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure and electronic structure of matter to be investigated at the atomic, molecular and macro scale, and over astronomical distances. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Current applications of spectroscopy include biomedical spectroscopy in the areas of tissue analysis and medical imaging. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIDAR
Lidar (, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranging, ranges by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. Lidar may operate in a fixed direction (e.g., vertical) or it may scan multiple directions, in a special combination of 3-D scanning and laser scanning. Lidar has terrestrial, airborne, and mobile applications. It is commonly used to make high-resolution maps, with applications in surveying, geodesy, geomatics, archaeology, geography, geology, geomorphology, seismology, forestry, atmospheric physics, laser guidance, airborne laser swathe mapping (ALSM), and Mars Orbiter Laser Altimeter, laser altimetry. It is used to make digital 3D modeling, 3-D representations of areas on the Earth's surface and ocean bottom of the intertidal and near coastal zone by varying the wavelength of light. It has also been in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
