Lithium Niobate - LiNbO3
LiNbO3, crystals are widely used as electro-optic modulators and Q-switches for Nd:YAG, Nd:YLF and Ti:Sapphire lasers, as well as the modulators for fiber optics. The following table lists the specifications of the typical LiNbO3 crystal used as Q-switch with transverse E-O modulation. The light beam travels in z-axis and electric field applies to x-axis. The electro-optic coefficients of LiNbO3 are: r33 = 32 pm/V, r31 = 10 pm/V, r22 = 6.8 pm/V at low frequency, and r33 = 31 pm/V, r31= 8.6 pm/V, r22 = 3.4 pm/V at high electric frequency.
LiNbO3 Q-Switch Specifications
| Typical Crystal Size | 9x9x35 mm3 or 4x4x15 mm3 |
| Tolerance of Size | Z-axis: ±0.2 mmX-axis and Y-axis: ±0.1 mm |
| Chamfer | less than 0.5 mm at 45o |
| Accuracy of Orientation | Z-axis: <± 5' X-axis and Y-axis: < ±10' |
| Parallelism | < 20" |
| Finish | 10/5 Scratch/Dig |
| Flatness | λ/8 at 633 nm |
| AR-Coating | R < 0.2% @ 1064 nm |
| Electrodes | Gold/Chrome plated on X-faces |
| Wavefront Distortion | < λ/4 @ 633 nm |
| Extinction Ratio | > 400:1 @ 633 nm, f6 mm beam |
LiNbO3 is also a good acousto-optic crystal and used for surface acoustic wave (SAW) wafer and A-O modulators. Gamdan offers acoustic (SAW) grade LiNbO3 crystals in wafers, as-cut boules, finished components and custom fabricated elements.
Typical Saw Properties
| Cut Type | SAW Velocity Vs (m/s) | Electromechanical Coupling Factork2s (%) | Temperature Coefficient of Velocity TCV (10-6/ o C) | Temperature Coefficient of Delay TCD (10-6/ o C) |
| 127.86 o Y-X | 3970 | 5.5 | -60 | 78 |
| Y-X | 3485 | 4.3 | -85 | 95 |
Typical Specifications:
| Specifications | Type | |||
| Boule | Wafer | |||
| Diameter | f3" | f4" | f3" | f4" |
| Length or Thickness (mm) | <100 | <50 | 0.35-0.5 | |
| Orientations | 127.86°Y, 64°Y, 135°Y, X, Y, Z, and other cuts | |||
| Ref. Flat Orientation | X, Y | |||
| Ref. Flat Length | 22±2mm 32±2mm 22±2mm 32±2mm | |||
| Front Side Polishing | Mirror polished 5-15 Å | |||
| Back Side Polishing | 0.3-1.0µm | |||
| Flatness(µm) | 25°C | 15 | ||
| Bow (µm) | 25 | |||
Datasheet (PDF)