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Lasers

Certain transparent materials with a small concentration of neodymium ions can be used in lasers as gain media for infrared wavelengths (1054–1064 nm), e.g. Nd:YAG (yttrium aluminium garnet), Nd:YAP (yttrium aluminium perovskite), Nd:YLF (yttrium lithium fluoride), Nd:YVO (yttrium orthovanadate), and Nd:glass. Neodymium-doped crystals (typically Nd:YVO) generate high-powered infrared laser beams which are converted to green laser light in commercial DPSS hand-held lasers and laser pointers.

Trivalent neodymium ion Nd was the first lanthanide from rare-earth elements used for the generation of laser radiation. The Nd:CaWO laser was developed in 1961. Historically, it was the third laser which was put into operation (the first was ruby, the second the U:CaF laser). Over the years the neodymium laser became one of the most used lasers for application purposes. The success of the Nd ion lies in the structure of its energy levels and in the spectroscopic properties suitable for the generation of laser radiation. In 1964 Geusic et al. demonstrated the operation of neodymium ion in YAG matrix Y Al O. It is a four-level laser with lower threshold and with excellent mechanical and temperature properties. For optical pumping of this material it is possible to use non-coherent flashlamp radiation or a coherent diode beam.

The current laser at the UK Atomic Weapons Establishment (AWE), the HELEN (High Energy Laser Embodying Neodymium) 1- terawatt neodymium-glass laser, can access the midpoints of pressure and temperature regions and is used to acquire data for modeling on how density, temperature, and pressure interact inside warheads. HELEN can create plasmas of around 10 K, from which opacity and transmission of radiation are measured.

Neodymium glass solid-state lasers are used in extremely high power (terawatt scale), high energy (megajoules) multiple beam systems for inertial confinement fusion. Nd:glass lasers are usually frequency tripled to the third harmonic at 351 nm in laser fusion devices.