Optical Grade Lithium Niobate Wafers
Lithium Niobate Wafers and Optical Grade LiNbO3 Substrates
Optical Grade Lithium Niobate Wafers, also written as LiNbO3 wafers or lithium niobate substrates, are single crystal wafers used for photonics, electro-optic modulators, phase modulators, PPLN waveguides, SAW devices, optical waveguides, nonlinear optics and precision optical components.
LiNbO3 is selected when a device needs strong electro-optic response, useful nonlinear optical coefficients, stable mechanical properties and broad optical transmission. For wafer buyers, the important details are not only diameter and thickness, but also cut orientation, stoichiometry, dopant, polishing type, surface roughness, TTV, bow, warp, edge criteria, particle control and inspection method.
ATR Crystal supplies optical grade lithium niobate wafers in 2 inch, 3 inch and 4 inch sizes, with X-cut, Y-cut, Z-cut, Y-135 and custom orientations. Available material options include congruent lithium niobate (CLN), near-stoichiometric lithium niobate (SLN), MgO:LiNbO3, Fe:LiNbO3, Er:LiNbO3, Tm:LiNbO3, Pr:LiNbO3, boules, blanks and customized optical components.
Applications of Lithium Niobate Wafers
Electro-optic modulators, phase modulators and optical switches
PPLN waveguides, nonlinear optics, SHG, OPO and frequency conversion
Integrated photonics and thin-film lithium niobate process development
SAW devices, acoustic wave filters and sensor substrates
Electro-optic Q-switches and laser optical components
Optical waveguide substrates, research wafers, boules and blanks
Advantages of Optical Grade LiNbO3 Wafers
- Electro-optic material platformLiNbO3 is widely used for electro-optic modulators, phase shifters, Q-switches and photonic devices.
- Nonlinear optical performanceLithium niobate is a standard material for PPLN, SHG, OPO, wavelength conversion and nonlinear optics research.
- Optical grade wafer processingOptical homogeneity, polish type, Ra, scratch-dig, flatness and particle control can be specified for photonics and waveguide applications.
- Multiple material gradesCLN, SLN, MgO-doped, Fe-doped, Er-doped, Tm-doped and Pr-doped LiNbO3 wafers can be reviewed by application.
- Custom orientation supportX-cut, Y-cut, Z-cut, Y-135, rotated cuts, orientation tolerance and primary flat direction can be reviewed according to drawing.
- Supplier-level inspection supportTTV, bow, warp, surface roughness, particles, edge defects, contamination and wafer-box packaging can be discussed before quotation.
Available LiNbO3 Wafer Options
Common lithium niobate wafer and LiNbO3 substrate options for engineering review.
| Item | Available Option | Design Notes |
|---|---|---|
| Diameter | 2 inch, 3 inch, 4 inch | Availability depends on material grade, orientation, thickness and quantity. |
| Orientation | X-cut, Y-cut, Z-cut, Y-135 and custom cuts | Orientation should match electro-optic, SAW, waveguide or nonlinear-optic design requirements. |
| Thickness | 0.18 mm and above; common values include 0.25 mm, 0.5 mm and 1.0 mm | Thickness tolerance and TTV should be confirmed with wafer diameter and polish type. |
| Surface type | SSP, DSP, DSL | Single-side polished, double-side polished or double-side lapped processing. |
| Material grade | CLN, SLN, MgO:LiNbO3, Fe:LiNbO3, Er:LiNbO3, Tm:LiNbO3, Pr:LiNbO3 | Doping and stoichiometry should be selected according to optical damage, photonics, nonlinear or research requirements. |
| Product form | Wafers, boules, blanks and customized optics | Custom shapes and optical components can be reviewed case by case. |
Product Parameters of Optical Grade Lithium Niobate Wafers
The following values summarize typical LiNbO3 wafer parameters. Final acceptance limits depend on material grade, wafer diameter, thickness, orientation, polishing type and inspection standard.
| Parameter | Typical Value / Option |
|---|---|
| Material | LiNbO3 single crystal |
| Curie temperature | Approx. 1142 °C; actual value may vary slightly with composition and material grade |
| Cutting angle | X-cut, Y-cut, Z-cut, Y-135 and custom cuts |
| Orientation tolerance | Typically ±15 arcmin, or tighter by review |
| Diameter | 2 inch, 3 inch and 4 inch |
| Diameter tolerance | Typically ±0.20 mm |
| Thickness | 0.18 mm and above; custom thickness available |
| Thickness tolerance | Typically ±0.025 mm, depending on wafer diameter and thickness |
| Primary flat length | 16 mm, 22 mm, 32 mm or custom flat according to wafer specification |
| TTV | Typically ≤5 µm; tighter limits may be available depending on wafer diameter, thickness, polishing type and grade |
| Bow | Maximum bow to be agreed according to wafer diameter, thickness and measurement method |
| Warp | Maximum warp to be agreed according to wafer diameter, thickness and measurement method |
| Orientation flat | According to the agreed wafer specification or customer drawing |
| Surface type | Single-side polished, double-side polished or double-side lapped |
| Polished side Ra | Typically <0.5 nm, subject to wafer grade and measurement method |
| Polished side surface quality | Typically S/D 20/10, or according to the agreed specification |
| Lapped side Ra | Typically 0.2-0.5 µm, or customized |
| Edge criteria | Edge profile, flat geometry and allowable edge chipping can be specified according to the customer drawing or applicable IEC 62276 requirements for SAW-grade wafers |
| Quality | Free of cracks; bubbles and inclusions controlled according to agreed inspection criteria |
| Optical doping | Er, Fe, MgO, Tm, Pr or other doped options by review |
| Refractive index | Typical no ≈ 2.286 and ne ≈ 2.203 at 632.8 nm; values depend on wavelength, temperature, composition and material grade |
| Wafer surface contamination | No visible non-removable stains under the agreed inspection method |
| Particles | Particle limits, minimum particle size, inspection area and measurement method to be agreed before production |
| Scratch and chipping | No cracks; scratches and edge chips controlled according to the agreed visual inspection and acceptance criteria |
| Defects | No cracks, saw marks or non-removable stains; inclusions, scratches and edge defects controlled according to agreed inspection criteria |
| Packaging | Typically 25 pcs per wafer box, or custom protective packing on request |
Available LiNbO3 Material Grades
Material grade and dopant type should be selected according to optical, photonic, nonlinear or acoustic device requirements.
| Material | Grade | Diameter | Growth / Cut Direction | Typical Use |
|---|---|---|---|---|
| LiNbO3 | Optical | 2 inch, 3 inch, 4 inch | X, Y, Z, Y-135 and custom cuts | Electro-optic, photonic, nonlinear, SAW and waveguide substrates |
| MgO:LiNbO3 | Optical | 2 inch, 3 inch | X or Z | High-power optical and nonlinear applications requiring improved photorefractive-damage resistance |
| Fe:LiNbO3 | Optical | 2 inch, 3 inch | Z | Photorefractive and holographic research applications |
| Tm:LiNbO3 | Optical | 2 inch, 3 inch | Z | Special optical and research applications |
| Pr:LiNbO3 | Optical | 2 inch, 3 inch | Z | Special optical and research applications |
| Er:LiNbO3 | Optical | 2 inch, 3 inch | X or Z | Active photonic and research substrates depending on device design |
Properties of Optical Grade Lithium Niobate Wafers
Typical physical and optical properties. Nonlinear and electro-optic coefficients should be confirmed according to material grade, wavelength, crystal composition and measurement method.
| Property | Typical Value |
|---|---|
| Growth method | Czochralski method |
| Crystal structure | Trigonal, point group 3m |
| Lattice constant | a = b = 5.148 A, c = 13.863 A |
| Melting point | Approx. 1250 C |
| Density | Approx. 4.64 g/cm3 |
| Mohs hardness | Approx. 5 |
| Refractive index | no = 2.286, ne = 2.203 at 632.8 nm |
| Nonlinear coefficient | Supplier-reported values include d33 around 34.45 pm/V, d31 and d15 around 5.95 pm/V, d22 around 13.07 pm/V; confirm convention and wavelength for final specification |
| Electro-optic coefficient | Typical reported values include r13 about 8.6 pm/V, r33 about 30.8 pm/V, r51 about 28.0 pm/V; r22 values vary by source and convention |
| Optical transmittance | Approx. 370-5000 nm, depending on grade, thickness, surface condition and measurement method |
| Thermal expansion | a11 = 15.4 x 10^-6/K, a33 = 7.5 x 10^-6/K |
LiNbO3 vs. Related Crystal Wafer Materials
LiNbO3 is usually selected when electro-optic modulation, nonlinear optics, PPLN or integrated photonics are the core requirements. LiTaO3 and quartz wafers may be better choices for some SAW, pyroelectric, thermal-stability or cost-driven substrate designs.
| Material | Common Use | Main Advantage | Design Notes |
|---|---|---|---|
| LiNbO3 | Electro-optic modulators, PPLN, photonics, nonlinear optics, SAW devices | Strong electro-optic and nonlinear optical properties with mature wafer processing | Orientation, stoichiometry, dopant, polish, TTV and surface quality are critical. |
| LiTaO3 | SAW devices, pyroelectric sensors, optical and nonlinear components | Good piezoelectric, pyroelectric and chemical stability characteristics | Often selected for SAW and pyroelectric applications. |
| Quartz | SAW filters, resonators, optical windows, precision substrates | Excellent thermal stability, low loss and mature wafer processing | Orientation such as ST-cut or 42.75 degree Y-X cut must be specified for SAW applications. |
| MgO:LiNbO3 | High-power nonlinear optics and PPLN-related work | Improved resistance to photorefractive damage compared with undoped LiNbO3 | MgO concentration, stoichiometry and poling requirements should be confirmed. |
| SLN | Advanced optical and nonlinear applications | Near-stoichiometric composition can improve certain optical characteristics | Availability, cost and wafer size should be checked early. |
Optical Grade vs SAW Grade Lithium Niobate
Optical grade lithium niobate wafers are selected when optical transmission, homogeneity, low scattering, surface quality and waveguide or modulator processing are important. SAW grade lithium niobate is normally optimized around acoustic device requirements, such as orientation and acoustic performance. If a project involves both optical and acoustic requirements, the wafer grade, cut angle and inspection criteria should be confirmed before price comparison.
Lithium Niobate Wafer Price and Cost Factors
Lithium niobate wafer price cannot be determined by diameter alone. The final quotation depends on material grade, crystal cut, dimensions, polishing, dimensional tolerances, surface quality, inspection requirements and order quantity.
| Pricing Factor | Details to Confirm |
|---|---|
| Material grade | Congruent, near-stoichiometric, MgO-doped or other doped LiNbO3 material. |
| Cut and dimensions | X-cut, Y-cut, Z-cut, rotated cut, diameter, thickness and orientation tolerance. |
| Surface processing | SSP, DSP or lapped surface, roughness, scratch-dig and edge requirements. |
| Geometry and inspection | TTV, bow, warp, flat direction, particles, defect criteria and inspection report. |
| Quantity and packaging | Prototype or batch quantity, wafer box, individual protection and export packing. |
For an accurate quotation, please provide the complete wafer specification and required quantity. Tighter tolerances, specialized material grades and advanced surface requirements normally require an individual technical review.
How to Specify Lithium Niobate Wafers
For LiNbO3 wafer orders, the most important specifications are material grade, stoichiometry, dopant, cut orientation, orientation tolerance, diameter, thickness, thickness tolerance, TTV, bow, warp, surface type, roughness, edge criteria, primary flat, particle control and packing method. Photonics and waveguide applications usually require tighter surface and roughness control than general substrate use.
For PPLN or nonlinear optics, confirm whether MgO doping, poling compatibility, domain design, optical homogeneity and damage-threshold requirements are needed. For TFLN or integrated photonics process development, the substrate supplier, polishing method, surface defect control and bonding/thinning process requirements should be reviewed before quotation.
Lithium Niobate Wafer Price Factors
Lithium niobate wafer price depends on diameter, thickness, cut orientation, material grade, dopant, polish type, TTV, bow, warp, surface roughness, particle requirements, inspection report and order quantity. A 2 inch standard CLN wafer and a custom MgO:LiNbO3 DSP wafer with tight TTV and Ra requirements should not be compared as the same product.
For a more accurate quotation, send the target application, wafer drawing, orientation, diameter, thickness, polishing requirement, quantity and inspection items. ATR Crystal can review whether a standard wafer specification is enough or whether a tighter optical-grade substrate is needed.
LiNbO3 Wafer RFQ Checklist
Providing the following information helps ATR Crystal review feasibility and quote more accurately.
| RFQ Item | Information to Provide |
|---|---|
| Application | EO modulator, PPLN, photonics, SAW device, waveguide substrate, Q-switch, sensor or custom optical component. |
| Material and grade | CLN, SLN, MgO:LiNbO3, Fe:LiNbO3, Er:LiNbO3, Tm:LiNbO3, Pr:LiNbO3 or other material requirement. |
| Orientation | X-cut, Y-cut, Z-cut, Y-135, rotated cut, orientation tolerance, primary flat direction and flat length. |
| Wafer geometry | Diameter, thickness, thickness tolerance, TTV, bow, warp, bevel and edge criteria. |
| Surface requirement | SSP, DSP or DSL; Ra, scratch-dig, particle limit, contamination limit and visual defect criteria. |
| Order information | Quantity, wafer box requirement, inspection report requirement, packaging, delivery schedule and drawing. |
Lithium Niobate Wafer RFQ Checklist
For an accurate LiNbO3 wafer quotation, please provide the application, material grade, dopant, cut orientation, diameter, thickness, thickness tolerance, TTV, bow, warp, surface type, roughness, primary flat, edge criteria, quantity and inspection report requirement. If the wafer is for photonics, electro-optic modulators, PPLN or SAW devices, please also confirm whether SSP, DSP or DSL surface processing is required.
