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YLF Laser Crystal

YLF laser crystal is the abbreviation for yttrium lithium fluoride (YLiF4). YLF is birefringent crystal, generally doped with neodymium (Nd_ and commonly used laser transitions occur at 1047 nm(grown along a-axis) and 1053 nm(grown along c-axis), although there are other rare-earth doped YLF crystals, like with ytterbium (Yb), erbium (Er), thulium (Tm), holmium (Ho) or praseodymium (Pr) doping.

It is an active laser medium in a solid-state laser, which is also used in near-infrared lasers. Pattern Wavelengths of Neodymium, Erbium, Holmium or Thulium doped Lithium Yttrium Fluorides:

Nd: YLF 1.047 µm, 1.053 µm, 1.313 µm, 1.324 µm, and 1.370 µm
Er: YLF 0.85 µm and 2.81 µm
Ho: YLF 0.75 µm and 2.06 µm
Tm: YLF 0.435 µm, 1.89 µm, and 2.30 µm

Neodymium-doped YLF crystal has a wide transparency range, low thermal lensing effect, and negative refractive index temperature coefficient, can achieve a large number of wavelength output, which is a high-performance laser crystal. 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.

Advantages Of high purity YLF laser crystal Include:

1.High power, low beam divergence, efficient single mode operation.
2.High average power Q-switched at a moderate repetition rate.
3.Linear polarized resonators for Q-switching and frequency doubling.
4.Potential uniform mode for large diameter rods or slabs.
Stimulated emission cross section and lifetime product are favorable for low CW threshold. 1.053 µm output matches gain curves of Nd: Glass and performs well as an oscillator and pre-amplifier for this host.

The combination of weak thermal lensing, large fluorescence line width, and naturally polarized oscillation make Nd: YLF an excellent material for CW, mode-locked operation. Welcome everyone to wholesale YLF laser crystal

Nd: YLF laser has an ability to yield higher pulse energies than Nd: YAG laser for repetition rates of a few kHz. It is mainly used in Q-switched systems owing to its relatively long fluorescence lifetime. As with Nd: YAG lasers, Q-switched Nd: YLF facilitates harmonic generation to produce shorter wavelengths. Nd: YLF lasers can be lamp-pumped or diode-pumped. When compared to Nd: YAG laser, Nd: YLF laser has low thermal conductivity. However, it exhibits weak thermal distortions to achieve high beam quality.

Physical Properties

Chemical Formula LiY 1.0-xNdxF4
Lattice Parameters a=5.16Å
Crystal Structure Tetragonal
Space Group I41/a
Nd atoms/cm3 1.40x1020 atoms/cm3 for 1% Nd doping,
Mohs Hardness 4 ~ 5
Melting Point 819℃
Density 3.99 g/cm3
Modulus of Elasticity 85 GPa
Thermal Expansion Coefficient 8.3x10-6/k ^c, ac=13.3x10-6/k ||c
Thermal Conductivity Coefficient 0.063 W/cm K
Specific Heat 0.79 J/g K

No doped YLF crystal is one of the rare-earth-doped laser materials with a variety of effects from the UV to mid–IR range. YLF has good optical properties with high transparency throughout the emission spectrum of the conventional sources used for pumping solid-state lasers. YLF does not show UV damage, and it has lower non-radiative decay rates for processes occurring between electronic levels participating in the pumping and lasing process.

No doped YLF crystal also has a low, two-photon absorption coefficient. Because of its low non-radiative rates, the material can be used for cascade emission between intermediate levels as well as an up-converter.

YLF is also a good medium for mode locking at 1047 or 1053 nm and 1.313 µm as a result of its natural birefringence and low thermal lensing. Mode-locked pulses from YLF are shorter thanks to its broader linewidth, both for the 1047/1053-nm and 1.313-µm emission peaks.

Optical Properties

Transparency Region 180nm to 6.7mm
Peak Simulation Emission Cross Section 1.8x10-19cm2 (E || c) at 1.047mm
1.2x10-19cm2 (E ^ c) at 1.053mm
Spontaneous Fluorescence Lifetime 485ms for 1% Nd doping
Scatter Losses <0.2% / cm
Peak Absorption Coefficient a=10.8cm-1 (792.0 nm E || c)
a=3.59cm-1 (797.0 nm E ^ c)
Refractive Indices Wavelength (nm) ne ne
262 1.485 1.511
350 1.473 1.491
525 1.456 1.479
1050 1.448 1.47
2065 1.442 1.464
Sellmeier Equations ni2(l) = A + Bl2/(l2-C) - Dl2/(l2-E)
no 3.38757 0.70757 0.00931 0.18849 50.99741
n2 1.31021 0.84903 0.00876 0.53607 134.956


  Wavelength(nm)   E∥c E⊥c
436     -2.44×10-6/℃     -0.54×10-6/℃
578 -2.86×10-6/℃ -0.91×10-6/℃
1060 -4.30×10-6/℃ -2.00×10-6/℃

Honour Optics supplies low price YLF laser crystal in rods and slabs with different cross-sections, dimensions, and coatings. Different dopants compositions with different concentrations are available for specific customer requirements. Nd: YLF is the most common lasing medium for diode-pumped and arc lamp-pumped solid-state lasers. Normally long YLF crystals for lamp pumping with standard concentration to 1.0 atom %, short YLF crystals used for diode pumping with concentration to 1.5 atom %.

Others like Er: YLF, Ho: YLF and Tm: YLF single crystal is designed to be applied in solid-state lasers which are widely used for industrial, medical and scientific applications. Pure YLF crystals are transparent within the spectrum band of 0.12 - 7.5 µm, photo-, thermal- and radiation-resistant. The YLF crystals have low values of nonlinear refraction index and thermos optical constants.


Doping concentration from 0.5 to 3.0mol%
Diameter from 2mm to 50.8 mm, length from 1mm to 180mm
Orientation Tolerance: 5 arc minutes
Dopant Concentration Tolerance------------------------0.1%
Parallelism --------------------------------------------------<10 arc seconds
Perpendicularity -------------------------------------------<5 arc minutes
Chamfer-----------------------------------------------------0.1mm @45°
Clear Aperture----------------------------------------------95%
Surface Quality---------------------------------------------10/5
Surface Flatness--------------------------------------------λ/10 @ 633nm
Wavefront Distortion--------------------------------------<λ/8@633nm

YLF laser crystal is birefringent, which eliminates thermally induced depolarization loss. The gain and the emission wavelength of Nd: YLF are polarization dependent: there is the stronger 1047nm line for π polarization and a weaker one at 1053nm for σ polarization. The 1053 nm line well fits the gain peak of Nd: glass, so Nd: YLF lasers are usually used as Nd: YLF laser-generator and preamplifier for the subsequent Nd: glass amplifiers.

Nd: YLF offers an alternative to the more common Nd: YAG host for near IR operation. The combination of weak thermal lensing (19 times lower than that of Nd: YAG), large fluorescence line width and naturally polarized oscillation make Nd: YLF an excellent material for CW, mode-lock operation. Q-Switch operation at a moderate repetition rate (~ 1 kHz). The linear polarized beam is ideal for Q-switching and frequency doubling. The 1053 nm output matches the gain profiles of Nd-glass and thus it can perform well as an oscillator or pre-amplifier for this Nd-glass laser host. Welcome everyone to wholesale YLF laser crystal.

Honour Optics supplies Nd, Pr, Er, Ho and no doped YLF crystals using the Czochralski technique. Honor Optics is a professional YLF laser crystal manufacturer, sell high purity YLF laser crystal, welcome to consult low price YLF laser crystal optimal price.