Yttrium aluminium garnet (YAG, Y₃Al₅O₁₂) is a synthetic crystalline material of the garnet group, used as the active laser medium in various solid-state lasers. General Name, Symbol, Number yttrium, Y, 39 Chemical series transition metals Group, Period, Block 3, 5, d Appearance silvery white Atomic mass 88. ... Aluminum is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... It has been suggested that crystallization processes be merged into this article or section. ... The garnet group of minerals show crystals with a habit of rhombic dodecahedrons and trapezohedrons. ... Within a laser, the active laser medium is the material that exhibits optical gain. ... A solid-state laser is a laser that uses a gain medium that is a solid, rather than a liquid such as dye lasers or a gas such as gas lasers. ...

YAG is used in jewelry as a diamond simulant. Colored variants are faceted and valued (as synthetics) for their clarity, durability, high refractive index and dispersion. Jewelry (the American spelling; spelled jewellery in Commonwealth English) consists of ornamental devices worn by persons, typically made with gems and precious metals. ... Due to its low cost and close visual likeness to diamond, cubic zirconia has remained the most gemologically and economically important diamond simulant since 1976. ...

YAG is commonly doped with other elements to obtain a specific laser wavelength e.g. Neodymium or Erbium to form Nd:YAG and Er:YAG lasers, respectively. In semiconductor production, doping refers to the process of intentionally introducing impurities into an intrinsic semiconductor in order to change its electrical properties. ... The wavelength is the distance between repeating units of a wave pattern. ... General Name, Symbol, Number neodymium, Nd, 60 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white, yellowish tinge Atomic mass 144. ... General Name, Symbol, Number Erbium, Er, 68 Chemical series Lanthanides Group, Period, Block NA, 6, f Density, Hardness 9066 kg/m3, ND Appearance silvery white Atomic properties Atomic weight 167. ...

Cerium-doped YAG (YAG:Ce) is used as a phosphor in applications ranging from cathode ray tubes to white LEDs. General Name, Symbol, Number cerium, Ce, 58 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 140. ... A phosphor is a substance that can exhibit the phenomenon of fluorescence (glowing during absorption of radiation of another kind) or phosphorescence (sustained glowing without further stimulus). ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT The cathode ray tube or CRT, invented by Karl Ferdinand Braun, is the display device that was traditionally used in most computer displays, video monitors, televisions, radar displays and oscilloscopes. ... Various light-emitting diodes (5 mm reds, 3 mm greens and yellows) A light-emitting diode (LED) is a semiconductor device that emits incoherent monochromatic light when electrically biased in the forward direction. ...

Properties

Color: Wide range of colors

Mohs’ hardness: 8.5

Refractive index: 1.833

Critical angle: 33°

Specific gravity: 4.55

Cleavage: Imperfect

Fracture: Conchoidal

Dispersion: Moderately high (.028)

Heat sensitivity: Low

Pleochroism: None

Birefringence: None

Crystal structure: Isometric

Treatments: YAG is a synthetic stone.

Cutting: Cuts similar to natural garnet.

Polishing: Alumina or diamond (50,000 or 100,000) common polishing laps.

Mohs can refer to: Friedrich Mohs Mohs Automobile Mohs scale of mineral hardness This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... The refractive index of a material is the factor by which the phase velocity of electromagnetic radiation is slowed relative to vacuum. ... In geometric optics, at a refractive boundary, the critical angle is the angle of incidence above which total internal reflection occurs. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... A conchoidal fracture is produced when some types of fine-grained mineral, such as obsidian and flint, are broken. ... Pleochroism is an optical phenomenon where due to double refraction of light by a colored gem or crystal, the light is divided into two paths which are polarized at a 90° angle to each other. ... A calcite crystal laid upon a paper with some letters showing the double refraction Birefringence, or double refraction, is the decomposition of a ray of light into two rays (the ordinary ray and the extraordinary ray) when it passes through certain types of material, such as calcite crystals, depending on... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... The garnet group of minerals show crystals with a habit of rhombic dodecahedrons and trapezohedrons. ... Aluminium oxide (or aluminum oxide) (Al2O3) is a chemical compound of aluminium and oxygen. ... For other uses, see Diamond (disambiguation). ...

Doped variations

Nd:YAG

Main article: Nd:YAG laser

Neodymium-doped YAG (Nd:YAG) was developed in 1960s. It is the most widely used active laser medium in solid-state lasers. It can be used in lasers utilizing frequency doubling and frequency tripling, and high-energy Q-switching. Its thermal conductivity is better and its fluorescence lifetime is about twice as long than Nd:YVO₄. It can be operated on power levels of up to kilowatts. It can be directly Q-switched with Cr⁴⁺:YAG. General Name, Symbol, Number neodymium, Nd, 60 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white, yellowish tinge Atomic mass 144. ... Within a laser, the active laser medium is the material that exhibits optical gain. ... A solid-state laser is a laser that uses a gain medium that is a solid, rather than a liquid such as dye lasers or a gas such as gas lasers. ... Q-switching, sometimes known as giant pulse formation, is a technique discovered circa 1962 by R.W. Hellwarth and F.J. McClung using electrically switched Kerr cell shutters and is a technique by which a laser can be made to produce a pulsed output beam. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Neodymium doped yttrium orthovanadate (Nd:YVO4) is one of the active laser medium for diode laser-pumped solid-state lasers. ...

Nd:YAG lases at 1064 nanometers and its best absorption band for pumping is 1 nm wide and located at 807.5 nm. [1]

The dopant concentration in commercially available Nd:YAG usually varies between 0.5-1.4 molar %. Higher dopant concentration is used for continuous wave lasers, lower concentration is suitable for pulsed lasers. Nd:YAG is pinkish-purple, lighter doped rods being less intensely colored than heavier-doped ones. As its absorption spectrum is narrow, the hue will depend on the type of light and will differ between sunlight and artificial light.

Er:YAG

Main article: Er:YAG laser

Erbium-doped YAG (Er:YAG) is an active laser medium lasing at 2940 nm. Its absorption bands suitable for pumping are wide and located between 600-800 nm, allowing for efficient flashlamp pumping. The dopant concentration used is high, about 50% of yttrium atoms is replaced. The Er:YAG laser crystals couple well into water and body fluids, making them especially useful for medicine and dentistry uses; it is used for treatment of tooth enamel and in cosmetic surgery. Er:YAG is used for noninvasive monitoring of blood sugar. The mechanical properties of Er:YAG are essentially the same as Nd:YAG. Er:YAG operates at relatively eye-safe wavelengths (while it hits the lens, it is absorbed in the eye so it does not damage retina), works well at room temperature, and has high slope efficiency. Er:YAG is pale-green colored. General Name, Symbol, Number Erbium, Er, 68 Chemical series Lanthanides Group, Period, Block NA, 6, f Density, Hardness 9066 kg/m3, ND Appearance silvery white Atomic properties Atomic weight 167. ... Tooth enamel is the hardest and most mineralized substance of the body , and with dentin and cementum is one of the three major parts of the tooth. ... In medicine, blood sugar is a term used to refer to levels of glucose in the blood. ... Human eye cross-sectional view. ...

Yb:YAG

Ytterbium-doped YAG (Yb:YAG) is an active laser medium lasing at 1030 nm, with a broad, 18 nm wide absorption band at 940 nm. It is one of the most useful mediums for high-power diode-pumped solid state lasers. The dopant levels used range between 0.2-30% of replaced yttrium atoms. Yb:YAG has very low fractional heating, very high slope efficiency, and no excited-state absorption or up-conversion, high mechanical strength and high thermal conductivity. Yb:YAG can be pumped by reliable InGaAs laser diodes at 940 or 970 nm. General Name, Symbol, Number Ytterbium, Yb, 70 Chemical series Lanthanides Group, Period, Block NA, 6, f Density, Hardness 6570 kg/m3, ND Appearance silvery white Atomic properties Atomic weight 173. ... Diode Pumped Solid State (DPSS) lasers are lasers made by pumping a crystal, for example, a ruby or a neodymium-doped yttrium aluminum garnet (YAG) crystal with a laser diode, usually one that emits infrared light. ... Indium gallium arsenide (InGaAs) is a semiconductor composed of indium, gallium and arsenic. ... A packaged laser diode with penny for scale. ...

Yb:YAG is a good substitute for 1064 nm Nd:YAG in high-power applications, and its frequency-doubled 515 nm version can replace the 514 nm argon lasers. Krypton laser is an ion laser, a type of gas laser using krypton ions as a gain medium, pumped by electric discharge. ...

Nd:Ce:YAG

Neodymium-cerium double-doped YAG (Nd:Ce:YAG, or Nd,Ce:YAG) is an active laser medium material very similar to Nd:YAG. The added cerium atoms strongly absorb in ultraviolet region, and transfer their energy to the neodymium atoms, increasing the pumping efficiency; its result is lower thermal distortion and higher power output than Nd:YAG at the same pumping. The lasign wavelength, 1064 nm, is the same as for Nd:YAG. The material has a good anti-UV irradiation property and low lasing threshold. Usually 1.1-1.4 % of Y atoms are replaced with Nd, and 0.05-0.1% with Ce. General Name, Symbol, Number neodymium, Nd, 60 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white, yellowish tinge Atomic mass 144. ... General Name, Symbol, Number cerium, Ce, 58 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 140. ... Ultraviolet (UV) radiation is electromagnetic radiation of a wavelength shorter than that of the visible region, but longer than that of soft X-rays. ... In optics, the lasing threshold is the lowest excitation level at which laser output is dominated by stimulated emission rather than by spontaneous emission. ...

Ho:Cr:Tm:YAG

Holmium-chromium-thulium triple-doped YAG (Ho:Cr:Tm:YAG, or Ho,Cr,Tm:YAG) is an active laser medium material with high efficiency. It lases at 2097 nm and can be pumped by a flashlamp or a laser diode. It is widely used in military, medicine, and meteorology. It operates at relatively eye-safe wavelengths, works well at room temperature, and has high slope efficiency. When pumped by a diode, the 781 nm band is used. Other major pump bands are located between 400-800 nm. The dopant levels used are 0.35 atom.% Ho, 5.8 atom.% Tm, and 1.5 at.% Cr. The rods have green color, imparted by chromium(III). General Name, Symbol, Number holmium, Ho, 67 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 164. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... General Name, Symbol, Number thulium, Tm, 69 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery gray Atomic mass 168. ...

Tm:YAG

Thulium-doped YAG (Tm:YAG) is an active laser medium operating at the relatively eye-safe wavelengh of 2010 nm. It is suitable for being diode-pumped. It can be tuned between 1930-2040 nm. A dual-mode Tm:YAG laser emits two frequencies separated by 1 GHz. General Name, Symbol, Number thulium, Tm, 69 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery gray Atomic mass 168. ...

Cr⁴⁺:YAG

Chromium(IV)-doped YAG (Cr:YAG) provides a large absorption cross section in the 0.9-1.2 micrometer spectral region, which makes it an attractive choice as a passive Q-switch for Nd-doped lasers. The resulting devices are solid-state, compact and low-cost. It has high damage threshold, good thermal conductivity, good chemical stability, is resistant to ultraviolet radiation, and is easily machined. It is replacing the more traditional Q-switching materials like lithium fluoride and organic dyes. The dopant levels range between 0.5-3 molar %. General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... Ultraviolet (UV) radiation is electromagnetic radiation of a wavelength shorter than that of the visible region, but longer than that of soft X-rays. ... Lithium fluoride, or LiF, is a compound of lithium and fluoride, white and a crystalline solid in appearance. ... Yarn drying after being dyed in the early American tradition, at Conner Prairie living history museum. ...

It can be used for passive Q-switching the diode or lamp pumped Nd:YAG, Nd:YLF, Nd:YVO4, Yb:YAG, and other neodymium and yttrium doped lasers at wavelengths between 1000-1200 nm.

Cr:YAG can be also used for tunable lasers with output adjustable between 1350-1550 nm. It can generate ultrashort (down to femtoseconds range) pulses when pumped at 1064 nm by a Nd:YAG laser. Tunable laser Tunable lasers are used in DWDM-systems to allow wavelength (frequency) changes triggered by the operator. ...

Cr:YAG was demonstrated in a non-linear optics application as a self-pumped phase-conjugated mirror in a Nd:YAG loop resonator. It provides compensation of both phase and polarization aberrations induced into the loop resonator. Nonlinear optics is the branch of optics that describes the behaviour of light in nonlinear media, that is, media in which the polarization P responds nonlinearly to the electric field E of the light. ...

Dy:YAG

Dysprosium-doped YAG (Dy:YAG) is a temperature-sensitive phosphor used in temperature measurements. The phosphor is excited by a laser pulse and its temperature-dependent fluorescence is observed. Dy:YAG is sensitive in ranges of 2950-1800 K. The phosphor can be applied directly to the measured surface, or to an end of an optical fiber. General Name, Symbol, Number dysprosium, Dy, 66 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 162. ... A phosphor is a substance that can exhibit the phenomenon of fluorescence (glowing during absorption of radiation of another kind) or phosphorescence (sustained glowing without further stimulus). ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... Optical fibers An optical fiber (or fibre) is a transparent thin fiber, usually made of glass or plastic, for transmitting light. ...

Sm:YAG

Samarium-doped YAG (Sm:YAG) is a temperature-sensitive phosphor similar to Dy:YAG. General Name, Symbol, Number Samarium, Sm, 62 Chemical series Lanthanides Group, Period, Block _ , 6 , f Density, Hardness 7353 kg/m3, no data Appearance silvery white Atomic properties Atomic weight 150. ...

Tb:YAG

Terbium-doped YAG (Tb:YAG) is a phosphor used in cathode ray tubes. It emits at yellow-green color, at 544 nm. General Name, Symbol, Number terbium, Tb, 65 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 158. ... A phosphor is a substance that can exhibit the phenomenon of fluorescence (glowing during absorption of radiation of another kind) or phosphorescence (sustained glowing without further stimulus). ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT The cathode ray tube or CRT, invented by Karl Ferdinand Braun, is the display device that was traditionally used in most computer displays, video monitors, televisions, radar displays and oscilloscopes. ...

Ce:YAG

Cerium(III)-doped YAG (Ce:YAG or YAG:Ce) is a phosphor, or a scintillator when in pure single-crystal form, with wide range of uses. It emits yellow light when subjected to blue or ultraviolet light, or to x-ray light. It is used in white light emitting diodes, as a coating on a high-brightness blue InGaN diode, converting part of the blue light into yellow, which then appears as white. Such light however gives suboptimal color fidelity of green and red colors, causing color distortion. The output color is also strongly dependent on temperature and current. General Name, Symbol, Number cerium, Ce, 58 Chemical series lanthanides Group, Period, Block ?, 6, f Appearance silvery white Atomic mass 140. ... A phosphor is a substance that can exhibit the phenomenon of fluorescence (glowing during absorption of radiation of another kind) or phosphorescence (sustained glowing without further stimulus). ... A scintillator is a device or substance that absorbs high energy (ionizing) electromagnetic or charged particle radiation then, in response, fluoresces photons at a characteristic Stokes-shifted (longer) wavelength, releasing the previously absorbed energy. ... A single crystal is a crystalline solid in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample. ... Various light-emitting diodes (5 mm reds, 3 mm greens and yellows) A light-emitting diode (LED) is a semiconductor device that emits incoherent monochromatic light when electrically biased in the forward direction. ...

Ce:YAG is also used in some mercury-vapor lamps as one of the phosphors, often together with Eu:Y(P,V)O₄ (yttrium phosphate-vanadate). It is also used as a phosphor in cathode ray tubes, where it has green (530 nm) to yellow-green (550 nm). When excited by electrons, it has virtually no afterglow (70 ns decay time). It is suitable for use in photomultipliers. A Mercury-vapor lamp is a gas discharge lamp which uses mercury in an excited state to produce light. ... Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT The cathode ray tube or CRT, invented by Karl Ferdinand Braun, is the display device that was traditionally used in most computer displays, video monitors, televisions, radar displays and oscilloscopes. ... Photomultipliers, or photomultiplier tubes (PMT) are extremely sensitive detectors of light in the ultraviolet, visible and near infrared. ...

Ce:YAG is used in PET scanners, high-energy gamma radiation and charged particle detectors, and high-resolution imaging screens for gamma, x-rays, beta radiation and ultraviolet radiation. Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three dimensional image or map of functional processes in the body. ... This article is about electromagnetic radiation. ... In physics, a charged particle is a particle with an electric charge. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Beta particles are high-energy electrons emitted by certain types of radioactive nuclei such as potassium-40. ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ...

Ce:YAG can be further doped with gadolinium. General Name, Symbol, Number gadolinium, Gd, 64 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 157. ...

See also

• Yttrium iron garnet
• Gadolinium gallium garnet
• Nd:YAG laser
• Er:YAG laser