Rare-earth-doped lithium yttrium fluoride (RE: LiYF4) is a type of laser crystal that has unique properties such as a high laser damage threshold, large emission cross-section, and broad tunability range. It has been extensively studied and optimized for laser applications in different fields.

RE: LiYF4 crystal is composed of lithium (Li+), yttrium (Y3+), and fluorine (F-) ions, and rare-earth dopants such as Ytterbium (Yb)Thulium(Tm)Holmium (Ho)Tm+Ho or Praseodymium(Pr) are incorporated into the crystal lattice. The crystal structure is tetragonal, belonging to the space group I41/a.

The use of RE: LiYF4 crystal in laser applications is expected to increase in the future due to its unique properties and advantages. Ongoing research is focused on developing new rare-earth dopants and optimizing the crystal's performance for specific laser applications. RE: LiYF4 crystal is expected to find new applications in areas such as laser communications, remote sensing, and military applications.


RE: LiYF4 crystal is used in various laser applications such as medical laser systems, spectroscopy, and scientific research. It is also used as a gain medium in tunable solid-state lasers and as a frequency-doubling crystal in high-power laser systems. RE: LiYF4 crystal doped with cerium (Ce3+) is used as a scintillation material for radiation detection and medical imaging.


RE: LiYF4 crystal has several key features and advantages that make it attractive for laser applications. These include:

—Small absorption loss in the ultraviolet spectral region
—Low nonlinear refractive index and thermo-optical constant
— the negative refractive index temperature coefficient can offset the thermal distortion, so as to output high-beam quality lase
—Higher slope efficiency and lower threshold compared with YAG crystal
—Better thermal stability than YAG crystal, with lower phonon energy and longer fluorescence life.
—High laser damage threshold: RE: LiYF4 crystal has a high resistance to laser-induced damage, which allows for high-power laser operation.
—Large emission cross-section: RE: LiYF4 crystal has a large absorption and emission cross-section, which results in efficient laser emission.
—Broad tunability range: RE: LiYF4 crystal can be doped with different rare-earth ions, which can broaden the laser tunability range.
—Low quantum defect: RE: LiYF4 crystal has a low quantum defect, which means that a high percentage of the pump energy is converted to laser radiation.

  • Name
    Rare-earth-doped lithium yttrium fluoride crystal (RE: LiYF4)
    Crystal Structure


    Lattice Constant

    a=5.16 Å c=4.85 Å



    Moss hardness


    Melt Point


    Thermal Conductivitya: 5.3 w/(mK); c: 7.2W(mK)
    Temperature coefficient of RIa: -14.3x10-6K-1; c: -10.1X10-6K-1(C)
    RI @1064no=1.448; ne=1.470

    Note: Re:LiYF4, Re~ Yb, Tm, Ho, Tm+Ho or Pr.

  • Dia.(2mm-36mm)*(2mm-50mm)