Lithium niobate (LiNbO3) crystals demonstrate maltitude photoelectric effects, including piezoelectric effect, electro-optic effect, nonlinear effect, photorefractive effect, photovoltaic effect, and photoelastic effect, acousto-optic effects and other optoelectronic properties, for this, LiNbO3 has been used in various applications such as Surface Acoustic Wave (SAW) filters, Electro-optic (EO) pockels cells, Phase Modulators, Optical Modulators, Optical Isolators, Optical Parametric Oscillators (OPO), Difference-Frequency Generation (DFG), Second Harmonic Generation (SHG), etc.
The lithium niobate crystals (LiNbO3) exhibit stable physical and chemical properties and are easy to process. Lithium niobate crystals have a wide light transmission range (0.3-5μm) and large electro-optic coefficients, which render them one of the most commonly used materials for EO pockels cells, optical modulators, and phase modulators with the advantage of low half-wave voltage and zero residual birefringences. However, LiNbO3 has a drawback of low damage threshold, therefore LiNbO3 pockels cells and modulators are fit for low and middle-power lasers. The damage threshold could be improved by MgO doping in LiNbO3, MgO:LiNbO3 has a higher damage threshold and could be utilized in high-power lasers.
Hangzhou Shalom EO offers off-the-shelf and custom LiNbO3 crystals and MgO:LiNbO3 crystals used for EO application of pockels cells and optical modulators, every piece of LiNbO3 crystals are under strict supervision and quality control, the AR coatings and Cr-Au electrodes are available upon request. A series of lithium-niobate products including SAW LiNbO3 Wafers, Nonlinear LiNbO3 and MgO:LiNbO3, MgO:LiNbO3 crystals for EO application, Optical Grade LiNbO3 Wafers, and MgO:PPLN Crystals, LiNbO3 Pockels Cells are also procurable.
Common Specifications:
| Crystal Materials | LiNbO3 crystals | Size | Customized |
| Size Tolerance | +/-0.1mm | Length Tolerance | +/-0.2mm |
| Surface Quality | 20/10 S/D | Parallelism | <20 arc seconds |
| Flatness | < Lambda/10 @633nm | Chamfer | 0.1-0.3mmx45° |
| Chips | <0.15mm | Side Surface | Fine ground |
| Orientation Tolerance | < 10 arc minutes | Wavefront Distortion | <Lambda/4@633nm |
| Extinction Ratio | >200:1 | Coating | AR/AR@1064nm or customized |
| Damaging Threshold | >100mW/cm^2@1064nm 10nS 10Hz pulse | Electrode on Side Surface | Chrome gold electrode (Cr+Au) |
Basic Properties:
| Crystal Structure | Trigonal, space group R3c | Cell Parameters | a = 5.15 Ang, c = 13.863Ang., Z = 6 |
| Melting Point | 1255±5℃ | Curie Point | 1140±5℃ |
| Mohs Hardness | 5 | Density | 4.64 g/cm3 |
| Absorption Coefficient | ~ 0.1%/cm @ 1064nm | Solubility | insoluble in H2O |
| Relative Dielectric Constant | eT11/e0: 85 eT33/e0: 29.5 |
Thermal Expansion Coefficients( @ 25℃) | ||a, 14.1 x 10-6 /K ||c, 4.1 x 10-6 /K |
| Thermal Conductivity | 38 W /m /K @ 25℃ | ||
Linear Optical Properties:
| Transparency Range | 420-5200nm | Optical Homogeneity | ~ 5 x 10-5 /cm |
| Refractive Indices | ne=2.146, no = 2.220 @ 1300nm ne= 2.156, no = 2.232 @ 1064nm ne= 2.203, no = 2.286 @ 632.8nm |
Sellmeier Equations (λ in mm) |
n2o (l) = 4.9048+0.11768/(l2 - 0.04750) - 0.027169l2 n2e (l) = 4.5820+0.099169/(l2 - 0.04443) - 0.021950l2 |
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 1300nm deff =5.3 pm/V or ~13.6 x d36(KDP) for OPO pumped at 1064nm 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 |
LiNbO3 crystals with brewster angle:
