Neodymium-doped yttrium lithium fluoride (Nd:YLF) is a

lasing medium The active laser medium (also called a gain medium or lasing medium) is the source of optical gain within a laser. The gain results from the stimulated emission of photons through electronic or molecular transitions to a lower energy state from ...

for

arc lamp An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc). The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the first decade of the 1800s, ...

- pumped and diode-pumped

solid-state laser A solid-state laser is a laser that uses a active laser medium, gain medium that is a solid, rather than a liquid as in dye lasers or a gas as in gas lasers. Semiconductor-based lasers are also in the solid state, but are generally considered as ...

s. The YLF crystal (LiYF₄) is naturally

birefringent Birefringence, also called double refraction, is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. These optically anisotropic materials are described as birefring ...

, and commonly used laser transitions occur at 1047 nm and 1053 nm. It is used in Q-switched systems in part due to its relatively long fluorescence lifetime. As with Nd:YAG lasers,

harmonic generation Harmonic generation (HG, also called multiple harmonic generation) is a nonlinear optical process in which n photons with the same frequency interact with a nonlinear material, are "combined", and generate a new photon with n times the energy of t ...

is frequently employed with Q-switched Nd:YLF to produce shorter wavelengths. A common application of frequency-doubled Nd:YLF pulses is to pump ultrafast Ti:Sapphire chirped-pulse amplifiers. Neodymium-doped YLF can provide higher pulse energies than Nd:YAG for repetition rates of a few kHz or less. Compared to Nd:YAG, the Nd:YLF crystal is very

brittle A material is brittle if, when subjected to stress, it fractures with little elastic deformation and without significant plastic deformation. Brittle materials absorb relatively little energy prior to fracture, even those of high strength. ...

and fractures easily. It is also slightly water-

soluble In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solubi ...

— a YLF laser rod may very slowly dissolve in cooling water which surrounds i

Physical and chemical properties

Materials: Nd:LiYF4 Modulus of Elasticity: 85 GPa Crystal Structure: Tetragonal Cell Parameters: a=5.16 Å, c=10.85 Å Melting Point: 819 °C Mohs Hardness: 4~5Nd:YLF Crystal
/ref> Density: 3.99 g/cm^3 Thermal Conductivity: 0.063 W/cm/K Specific Heat: 0.79 J/g/K

References

Laser gain media Crystals Neodymium compounds Yttrium compounds Lithium compounds Fluorides {{Optics-stub

Physical and chemical properties

See also

References