Introduction of LiNbO3

LiNbO3 is widely used as electro-optic modulators and Q-switches for Nd:YAG, Nd:YLF and Ti:Sapphire lasers as well as modulators for fiber optics. The following table lists the specifications of a typical LiNbO3 crystal used as Q-switch with transverse E-O modulation. The light propagates 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. The half–wave voltage: Vπ=λd/(2no3r22L), r c=(ne/no)3r33-r13.

LiNbO3 Q-Switch Specifications

Size 9 X 9 X 25 mm3 or 4 X 4 X 15 mm3
Other size is available upon request
Tolerance of size Z-axis: ± 0.2 mm
X-axis and Y-axis:±0.1 mm
Chamfer less than 0.5 mm at 45°
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, φ6 mm beam

LiNbO3 is also a good acousto-optic crystal and used for surface acoustic wave (SAW) wafer and A-O modulators. Photonchina provides 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 Factor
k2s (%)
Temperature Coefficient of Velocity
TCV (10-6/oC)
Temperature Coefficient of Delay
TCD (10-6/oC)
127.86o Y-X 3970 5.5 -60 78
Y-X 3485 4.3 -85 95


Typical Specifications

Type Specifications Boule Wafer
Diameter Φ3″ Φ4″ Φ3″ Φ4″
Length or Thickness(mm) ≤100 ≤50 0.35-0.5
Orientation 127.86°Y, 64°Y, 135°Y, X, Y, Z, and other cut
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 Lapping 0.3-1.0 mm
Flatness (mm) ≤ 15
Bow (mm) ≤ 25

Size and specification of wafers upon request is available.