Neodymium-doped yttrium lithium fluoride
Neodymium-doped yttrium lithium fluoride is a lasing medium for arc lamp-pumped and diode-pumped solid-state lasers. The YLF crystal is naturally birefringent, 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 s, harmonic generation 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
and fractures easily. It is also slightly water-soluble — a YLF laser rod may very
slowly dissolve in cooling water which surrounds it.