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Materials>Crystals>Lithium Niobate Crystal Series
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Lithium Niobate Crystal (LiNbO3)

LiNbO3 Crystal is widely used as frequency doublers for wavelength > 1mm and optical parametric oscillators (OPOs) pumped at 1064 nm as well as quasi-phase-matched (QPM) devices. Due to its large Electro-Optic (E-O) and Acousto-Optic (A-O) coefficients, LiNbO3 crystal is the most commonly used material for Pockel Cells, Q-switches and phase modulators, waveguide substrate, and surface acoustic wave (SAW) wafers, etc.

AZURE provides high quality and large size LiNbO3 crystals for laser frequency doublers, OPOs and quasi-phase-matched doublers, as well as waveguide substrate and SAW wafers. High quality LiNbO3 components with aperture of (2 - 15) x (2 - 15) mm2 and length up to 50 mm for frequency doublers and optical parametric oscillators (OPOs), 50x50x1 mm3 or Dia. 3" x 1 mm LiNbO3 substrate for waveguide optics, and Dia. 3" SAW wafers are available with high volume and at low price.

1. Basic Properties

Crystal Structure

Trigonal, space group R3c

Cell Parameters

a = 0.515, c = 13.863, Z = 6

Melting Point


Curie Point


Mohs Hardness



4.64 g/cm3

Absorption Coefficient

~ 0.1%/cm @ 1064 nm


insoluble in H2O

Relative Dielectric Constant

eT11/e0: 85
eT33/e0: 29.5

Thermal Expansion Coefficients( @ 25oC)

||a, 2.0 x 10-6/K ||c, 2.2 x 10-6/K

Thermal Conductivity

38 W /m /K @ 25oC

2. Linear Optical Properties

Transparency Range  420-5200nm

Refractive Indices
ne=2.146, no = 2.220 @ 1300 nm
ne= 2.156, no = 2.232 @ 1064 nm
ne= 2.203, no = 2.286 @ 632.8nm

LiNbO3 Transparency Curve

Optical Homogeneity ~ 5 x 10-5 /cm

Sellmeier Equations (l in mm):

n2o (l) = 4.9048+0.11768/(l2 - 0.04750) - 0.027169l2

n2e (l) = 4.5820+0.099169/(l2 - 0.04443) - 0.021950l2

3. Nonlinear Optical Properties

NLO Coefficients

d33 = 34.4 pm/V
d31 = d15 = 5.95 pm/V
d22 = 3.07 pm/V

Efficiency NLO Coefficients

deff =5.7 pm/V or ~14.6 x d36 (KDP) for frequency doubling 1300 nm;
deff =5.3 pm/V or ~13.6 x d36 (KDP) for OPO pumped at 1064 nm;
deff =17.6 pm/V or ~45 x d36 (KDP) for quasi-phase-matched structure.

Electro-Optic Coefficients

gT33 = 32 pm/V,  gS33 = 31 pm/V,
gT31 =10 pm/V,  gS31=8.6 pm/V,
gT22 = 6.8 pm/V, gS22= 3.4 pm/V,

Half-Wave Voltage, DC
Electrical field
||z, light ^z:
Electrical field
||x or y, light||z:

3.03 KV
4.02 KV

Damage Threshold

100 MW/cm2 (10 ns, 1064nm)

4. Standard Specifications of laser grade LiNbO3 crystals:

Transmitted wavefront distortion

better than l/4 @ 633nm

Dimension tolerance

(W0.1mm) x (H0.1mm) x (L0.2mm)

Clear aperture

over 90% central diameter


l/8 @ 633nm

Surface quality

20 /10 Scratch/Dig


better than 20 arc sec


5 arc min

Angle tolerance

Dq < 0.5o, Df < 0.5o


dual wave band AR coating at 1064/532 nm on both surfaces, with R < 0.2% at 1064 nm and R < 0.5% at 0.532 nm per surface

  • Magnesium Oxide Doped Lithium Niobate Crystals (MgO:LiNbO3)

Compared with LiNbO3 crystal, MgO:LiNbO3 crystal exhibits its particular advantages for NCPM frequency doubling (SHG) of Nd:Lasers, mixing (SFG) and optical parametric oscillators (OPOs). The SHG efficiencies
of over 65% for pulsed Nd:YAG lasers and 45% for cw Nd:YAG lasers have been achieved in MgO:LiNbO3 crystals, respectively. MgO:LiNbO3 is also a good crystal for optical parametric oscillators (OPOs) and amplifiers (OPAs), quasi-phase-matched doublers and integrated waveguide.

MgO:LiNbO3 has similar effective nonlinear coefficients to pure LiNbO3. Its Sellmeier equations (for MgO dopant 7 mol%) are:

 n2o (l) = 4.8762+0.11554/(l2 - 0.04674) - 0.033119 x l2      (l in um)

n2o (l) = 4.5469+0.094779/(l2 - 0.04439) - 0.026721 x l2      

AZURE provides high quality MgO:LiNbO3 crystals for various nonlinear optics (NLO) and E-O applications. The typical size of MgO:LiNbO3 crystals is (3 - 10) x (3 - 10) x (10 - 30) mm3 for OPOs & OPAs and frequency doubling & mixing, and 20x20x1 mm3 for waveguide substrates. Other specs. and AR-coatings for MgO:LiNbO3 are available upon request.


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Lithium Niobate Crystal Series