High optical gain in erbium-doped potassium double tungstate channel waveguide amplifiers.

See more Erbium products. Erbium (atomic symbol: Er, atomic number: 68) is a Block F, Group 3, Period 6 element with an atomic radius of 167.259. The number of electrons in each of Erbium's shells is [2, 8, 18, 30, 8, 2] and its electron configuration is [Xe]4f¹² 6s². The erbium atom has a radius of 176 pm and a Van der Waals radius of 235 pm. Erbium was discovered by Carl Mosander in 1843. Sources of Erbium include the mineral monazite and sand ores. Erbium is a member of the lanthanide or rare earth series of elements. In its elemental form, erbium is soft and malleable. It is fairly stable in air and does not oxidize as rapidly as some of the other rare earth metals. Erbium's ions fluoresce in a bright pink color, making them highly useful for imaging and optical applications. It is named after the Swedish town Ytterby where it was first discovered.

See more Tungsten products. Tungsten (atomic symbol: W, atomic number: 74) is a Block D, Group 6, Period 6 element with an atomic weight of 183.84. The number of electrons in each of tungsten's shells is [2, 8, 18, 32, 12, 2] and its electron configuration is [Xe] 4f¹⁴ 5d⁴ 6s². The tungsten atom has a radius of 139 pm and a Van der Waals radius of 210 pm. Tungsten was discovered by Torbern Bergman in 1781 and first isolated by Juan José Elhuyar and Fausto Elhuyar in 1783. In its elemental form, tungsten has a grayish white, lustrous appearance. Tungsten has the highest melting point of all the metallic elements and a density comparable to that or uranium or gold and about 1.7 times that of lead. Tungsten alloys are often used to make filaments and targets of x-ray tubes. It is found in the minerals scheelite (CaWO₄) and wolframite [(Fe,Mn)WO₄]. In reference to its density, Tungsten gets its name from the Swedish words tung and sten, meaning heavy stone.

See more Potassium products. Potassium (atomic symbol: K, atomic number: 19) is a Block S, Group 1, Period 4 element with an atomic weight of 39.0983. The number of electrons in each of Potassium's shells is [2, 8, 8, 1] and its electron configuration is [Ar] 4s¹. The potassium atom has a radius of 227.2 pm and a Van der Waals radius of 275 pm. Potassium was discovered and first isolated by Sir Humphrey Davy in 1807. Potassium is the seventh most abundant element on earth. It is one of the most reactive and electropositive of all metals and rapidly oxidizes. As with other alkali metals, potassium decomposes in water with the evolution of hydrogen because of its reacts violently with water, it only occurs in nature in ionic salts. In its elemental form, potassium has a silvery gray metallic appearance, but its compounds (such as potassium hydroxide) are more frequently used in industrial and chemical applications. The origin of the element's name comes from the English word 'potash,' meaning pot ashes, and the Arabic word qali, which means alkali. The symbol K originates from the Latin word kalium.