Lithium Niobate (LiNbO3) Crystal Substrates (5pack)

We can make LiNbO₃ substrates in all of these common sizes: 5x5mm, 10x10mm, 20x20mm, 2”, 3”, 4” diameters. Please get in touch if you would like a quote for another size. LiNbO₃ PPLN is also available. 

• Name:  LiNbO₃, Lithium Niobate Single Crystal Substrates
• Lattice parameter:a= 5.418Å, c= 13.863 Å 
• Crystal Structure: Trigonal
• Commonly used as substrate for: Surface acoustic wave (SAW) devices, ZnO, YBCO, 
• Surface Roughness: Ra <0.5 nm (measured 5x5 µm AFM scan)
• Available Dimensions: 5x5 mm to 4 inch diameter and customized
• Single or double side polished
• Cut to order (3 weeks)

Common orientations of LiNbO₃ wafers are Z-cut (0001), X-cut (11-20), Y-cut (10-10) and Y-X cut 

This is the different nomenclature referring to the surface acoustic wave properties of the material for which this material is best known and commonly used in single crystal form. Z-Cut is the most common, X-Cut quartz are cut at an angle of 35 degrees to the Z axis. Y cut are cut at an angle of 90 to the Z axis

Lithium niobate (LN) is a ferroelectric material with excellent electro-optic, nonlinear, and piezoelectric properties. Lithium niobate crystals are technically important materials for optical waveguides, mobile phones, piezoelectric sensors, optical modulators and various other linear and non-linear optical applications. It is transparent for wavelengths between 350 and 5200 nanometers.

As it is commonly used in devices, this synthetic material is readily available in single crystal form up to 4 inch diameter and has been used as a substrate for many thin films for example YBCO and ZnO. most commonly however, LiNbO₃ used to make devices due to it interesting properties: .e. Electro-optical modulation, Q-switching and Laser frequency conversion of wavelengths (>1 µm).

Periodically poled lithium niobate (PPLN) is a domain-engineered lithium niobate crystal, used mainly for achieving quasi-phase-matching in nonlinear optics. The ferroelectric domains point alternatively to the +c and the −c direction, with a period of typically between 5 and 35 µm. The shorter periods of this range are used for second harmonic generation, while the longer ones for optical parametric oscillation. Periodic poling can be achieved by electrical poling with periodically structured electrode. If you need PPLN then please email us with your requirements. 

LiNbO₃ wafers are a good choice for generating nonlinear signal, sum frequency or second harmonic generation

LiNbO₃ X-cut  (11-20):

X-cut lithium niobate is a material with a crystalline structure that has been cut along the x-axis. This crystal can be used in a variety of optical and acousto-optical applications such as frequency-shifting, phase modulation, and waveguide fabrication.

In an X-cut crystal, the electric field is applied along the X-axis. The Miller indices (11-20) correspond to the crystallographic directions in terms of the Miller indices (hkl). In this case, it means the cut is made along the crystallographic direction [1120]. This cut is often used in various optical devices.

LiNbO₃ Y-cut  (10-10):

Y-cut lithium niobate is a material with a crystalline structure that has been cut along the y-axis. This crystal can be used in a variety of optical and acousto-optical applications such as optical switching, polarization manipulation, and optical parametric generation.

In a Y-cut crystal, the electric field is applied along the Y-axis. The Miller indices (10-10) correspond to the crystallographic direction [100]. This cut is often used in applications where a specific refractive index is required.

LiNbO₃ Z-cut (0001):

Z-cut lithium niobate is a material with a crystalline structure that has been cut along the z-axis. This crystal can be used in a variety of optical and acousto-optical applications such as second harmonic generation, wavelength conversion, and optical parametric oscillation. The different experimental set up requirements for each of these types of lithium niobate depend on the specific application. For example, an experiment requiring second harmonic generation would need a z-cut lithium niobate crystal, while an experiment requiring frequency-shifting would need an x-cut lithium niobate crystal. In general, the experimental set up requirements for each type of lithium niobate will depend on the application and the specific parameters of the experiment.

In a Z-cut crystal, the electric field is applied along the Z-axis. The Miller indices (0001) correspond to the crystallographic direction [0001]. This cut is commonly used for nonlinear optics and acousto-optic devices.

LiNbO₃ Y-X-cut:

Y-X cut lithium niobate is a material with a crystalline structure that has been cut with the surface parallel to the Y-axis, and the propagation direction along the X-axis. This orientation is frequently used in optical and surface acoustic wave (SAW) devices, particularly for wave propagation control, electro-optic modulation, and frequency filtering.

In a Y-X cut crystal, the electric field is applied along the X-axis while the Y-axis defines the orientation of the cut. The Miller indices (10-12) correspond to the crystallographic direction [1012]. This cut is often chosen in applications where specific acoustic or optical properties, such as velocity matching or polarization control, are required.

LiNbO₃ Y-X cut 36°, Y-X cut 64° and Y-X cut 128°. 

For Y-X cut substrates / wafers there is a defined cut angle as well. Y-X cut 36°, Y-X cut 64° and Y-X cut 128°. The first letter corresponds to the starting position of the wafer and the second letter is the axis which the it is rotated about and the angle, is how far it is rotated about this axis. So for Y-X 128 degrees, we start at the Y plane and rotate the crystal about the X-axis 128 degrees and the cut is made at this point. Shown in blue in the image below. 36 deg Y-X cut with flat orientation:  X cut (11-20). 

For Y-X 128 degrees, the, Primary Flat is normal to the X axis, the secondary flat is 90 degree clockwise from the primary flat when viewing the polished face <+Z/-Y>

Trigonal Crystal System:

LiNbO₃ is a member of the trigonal crystal system so is denotes in hexagonal (4 indices) format.

In this arrangement, the Z-axis is perpendicular to both the X and Y axes. However, the X and Y axes are not necessarily perpendicular to each other; they are oriented in the plane perpendicular to the Z-axis.

Below is a good schematic, although in 3-indices notation:-

Below is a schematic description of X-Y cuts, common for SAW applications - 

For more information I recommend this paper on SAW applications "Surface AcousticWave (SAW) Sensors: Physics, Materials, and Applications, Debdyuti Mandal and Sourav Banerjee"

If you have any questions please contact us on info@crystalsubstrates.com

Dr Joseph Franklin