Garnet laser material

Neodymium-doped yttrium-aluminum garnet is among the most commonly applied laser material and has broad application (neodymium-YAG). 

Silver-colored, ductile metal that is attacked slowly by air and water. The element exhibits interesting magnetic properties. Found in television tubes. Laser material such as YAG (yttrium-aluminum garnet) doped with holmium (as well as chromium and thulium) can be applied in medicine, especially in sensitive eye operations. 

The yttrium aluminum garnet crystal, Y3 AI5O12, doped withNd + ions, is a well-known solid state laser material (abbreviated to Nd YAG). If the fluorescence lifetime of the main laser emission is 230 /rs and the quantum efficiency of the corresponding emitting level is 0.9, determine (a) the radiative lifetime and... 

Some of the most commonly used solid state lasers by far are the Nd + based lasers, such as the Nd YAG laser (Nd + ions in yttrium aluminum garnet), Ndrglass materials, or more recently the Nd YLF or Nd YV04 lasers. Nd + lasers operate in a four-level scheme and they are optically pumped either by a flashlamp or, for a more... 

Geusic et al. (118) made measurements of the fluorescent lifetime of neodymium in yttrium aluminum garnet (Y3A15012). For neodymium concentrations up to 3 atomic per cent, the measured fluorescent-decay time is approximately 200 jtxsec at both IT and 300°K. Above 6 atomic per cent, a marked decrease in the fluorescent lifetime is observed. They suggest that this is due to neodymium interactions. It is to be noted that yttrium aluminum garnet is a laser material of very exceptional quality. 

Figure 20-8 Increasing monochromator bandwidth broadens the bands and decreases the apparent absorbance of Pr34 in a crystal of yttrium aluminum garnet (a laser material). [Courtesy M. D. Seltzer, Mlchelson Laboratory, China Lake, CAJ...

Due to its unique spectroscopic and emission dynamic properties, Nd " ion can be used for laser emission over a wide range of temporal regimes, from CW to very short pulses of below picosecond. The transitions from the two Stark levels of the manifold F3/2 to the Stark levels of the manifolds " ll 1/2, and " Ii3/2, corresponding to the ranges of 0.9, 1.0, and 1.3 pm, respectively, showed pretty large emission cross sections. Various cubic crystalline materials, including garnets and sesquioxides, have been used as hosts for Nd laser emission, which formed the major part of ceramic laser materials. 

Nd YAG is still the most popular Nd-doped garnet ceramic laser materials. At room temperature, the transitions of " p3/2 (R,) " ll 1/2 (Y ) have several lines with sufficiendy large emission cross sections, which can be used for laser emission. The most intense and widely used emission line is at 1064.15 nm, with emission cross sections of 2.8-3 x 10 cm, which is based mainly on the transition of 2 3, with a minor contribution from the transition of 1 2. In this transition, there are various other lines for potential laser emission, which include 2 1 at 1052.1 nm... 

The TM ions usually used for passive g-switching of infrared solid-state lasers include Cr" " (940-1100 nm range), (1.30-1.35 pm), and Co " (1.3-1.6 pm). Although aU these ions can be doped in cubic materials, i.e., Cr and in garnets and Co " in spinels, only Cr YAG ceramics have been reported for ceramic SA g-switches [37, 42, 132, 133]. The SA materials are usually used as components together with the Nd laser-active materials in the cavity. In this case, if the laser materials and the g-switch materials have a same host, such as Nd YAG lasers passively g-switched with Cr" YAG, the difference in refractive index between them should be very small, so that there is no reflection at the interface when the two materials are intimately joined. For single crystals, they can be either diffusively bonded or mechanically clamped. In contrast, when one or both of them... 

Mode-locked Yb-doped ceramic lasers discussed in the part include garnets and sesquioxides. Mode lockings of Yb YAG ceramic lasers under CW 940 or 968 nm diode laser pumping by using SESAMs have been reported [249, 250]. In this case, the duration of the pulse was limited to several hundreds of femtoseconds, due to the relatively narrow emission lines. The Yb concentration was usually about 10 at %, while the emission wavelength, either 1030 or 1048 nm, was selected according to the thickness of the laser materials or the transmission of the output mirrors. 

The solid phase lends itself to the preparation of lanthanide arrays. Indeed, lanthanide doped yttrium aluminium garnets are weU known as laser materials, while doped materials containing more than one kind of lanthanide have proved very effective at upconversion of energy - the sequential absorption of two photons giving rise to anti-Stokes emission [9]. In such systems, excited state absorption by the intermediate state gives rise to formation of a high energy... 

For all their usefulness, gas lasers are very inefficient lasers, with normally much less than 0.1 per cent conversion of electrical energy into laser light. A very widely used solid-state laser material is Nd YAG (and various similar doping/host material combinations). The abbreviation Nd YAG stands for neodymium atoms (Nd) being implanted in an yttrium aluminium garnet crystal host (Y3AI5O12). These implants, in the form of triply ionized neodymium Nd, form the actual active laser medium. 

Ca3(AI,Fe)2(SiOj3 from Nord-mark, Filipstad in central Sweden. Special garnets containing yttrium (and neodymium) are important laser materials. 

Synthetic garnets have excellent optical properties. Aluminum garnets are excellent crystal hosts and they are useful as solid state laser materials. Iron garnets have interesting infrared properties. The magnetic optical effects in iron garnets are not only useful in devices, but also provide fundamental information about the materials themselves. Finally, silicon-doped iron garnets have pho-... 

Synthetic gemstone materials often have multiple uses. Synthetic mby and colodess sapphire are used for watch bearings, unscratchable watch crystals, and bar-code reader windows. Synthetic quartz oscillators are used for precision time-keeping, citizen s band radio (CB) crystals, and filters. Synthetic mby, emerald, and garnets are used for masers and lasers (qv). 

Solid-state lasers using substitutional neodymium (Nd3+ ions) as the active defects are widely available. Practical lasers contain about 1% Nd3+ dopant. The most common host materials are glass, yttrium aluminum garnet (YAG), Y3A15012, and calcium tungstate, CaW04. In the crystalline host structures, the defects responsible for amplification are NdY and Ndca-... 

Among the best-known garnets Y3Fe2Fe3012 (Y3Fe5012 yttrium-iron garnet YIG) for its magnetic properties and applications, Y3A15012 (YAG, important laser host material). 

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