| Introduction | LiNbO3 | MgO:LiNbO3 | ZnO:LiNbO3 | Nd:MgO:LiNbO3 | Fe:LiNbO3 |
|
Due to its specific properties shown as follows, LiNbO3 is
commonly used as not only frequency doubler (wavelength > 1 mm)
but optical parameter oscillator (OPO) pumped at 1.064 mm, as
well quasi-phase-matched (QPM) doubler. Beijing Gospel OptoTech Co. (GOT)
supplies laser-grade LiNbO3 devices of (2-18) x (2-18) mm2 aperture
and up to 50 mm length for frequency doubler and optical parameter oscillator, with high
quality, large quantity and cheap price. |
Basic Properties |
| Density | 4.64 g/cm3 |
| Crystal Structure | Trigonal, 3m-point group |
| Lattice Parameters | a=b=0.515, c=13.863, Z=6 |
| Mohs Hardness | ~ 5 |
| Melting Point | 1250 oC |
| Curie Point | 1160 oC |
| Relative Dielectric Constant | e11T/e0 = 85; e33T/e0 = 29.5 |
| Absorption Coefficient | ~ 0.1%/cm@1.064 mm |
| Thermal Conductivity | 38 W/m/oC at 25oC |
| Thermal Expansion Coefficient | a1=a2 =2x10-6/oC, a3=2.2x-6/ oC at 25oC |
|
| Transparency Region | 0.40 mm ~ 4.5 mm | ||
| Optical Homogeneity | Dn ~ 5x10-5/cm | ||
| Nonlinear Coefficients | deff=13.6 d36(KDP) - OPO @ 1.064 mm | ||
| deff=14.6 d36(KDP) - SHG @1.30 mm | |||
| deff=45.0 d36(KDP) - QPM | |||
| Refractive Indexes | no | ne | |
| 2.220 | 2.146 | at 1.30 mm | |
| 2.322 | 2.156 | at 1.064 mm | |
| 2.286 | 2.203 | at 0.633 mm | |
| Sellmeier Equations (l in mm) | no2 = 4.9048+0.11768/(l2-0.0475)-0.027169l2 | ||
| ne2 = 4.5820+0.099169/(l2-0.04443)-0.02195l2 | |||
| Electro-optic Coefficients (pm/V) | Low frequency | High frequency | |
| g33 | 32 | 31 | |
| g31 | 10 | 8.6 | |
| g22 | 6.8 | 3.4 | |
| Damage Threshold | > 250 KW/ cm2 at 1.064 mm. (10 ns) | ||
LiNbO3 single crystal is also commonly used as an excellent material for surface acoustic wave (SAW) devices (such as filters, oscillators and resonators) and ultrasonic transducer due to its considerably high electro-mechanical coupling factor, low acoustic transmission loss, stable physical and chemical properties. GOT can supply large quantities of LiNbO3 boules, as-cut or finished f 3" wafers available up to 5,000~ 8,000 pieces per month with good quality and very low price. Please find the following basic specifications for LiNbO3 SAW wafer. |
|
| Standard Size | (f 3"`0.01") x (0.51 ` 0.05)mm |
| Orientation | (1)127.86o Y-cut; (2)YZ-cut; (3)41o or 64o Y-cut |
| Surface Finish | one surface mirror polished to Ra less than 10 C, reverse surface fine ground |
| SAW Velocity | 3485 m/s (Y-cut), 3970 m/s (127.86o Y-cut) |
| Electromechanical Coupling Factor | K31=0.023, Z00Kt=0.17 |
| Temperature Coeff. of Delay (TCD) | 78X10-6/oC (127.86o Y-cut) |
| Temperature Coeff. of Velocity (TCV) | -60X10-6/oC (127.86oY-cut) |
LiNbO3 is also extensively used as electro-optic modulator and Q-switch for Nd:YAG, Nd:YLF and Ti:Sapphire lasers as well as modulator for fiber optics, etc. The transverse modulation is mostly employed for LiNbO3. If a LiNbO3 crystal is used as Q-switch crystal with specifications listed as the following, the light propagates in Z-axis and electric field applies to X-axis, the refractive retardation will be G =p Lno3g22V/ld. MgO:LiNbO3 and ZnO:LiNbO3 crystals have similar electro-optic properties to LiNbO3 but with higher damage threshold. |
|
| Standard Dimension | 9x9x25 or 10x10x20mm3 (other sizes also available) |
| Dimension Tolerance | `0.1mm (X & Y-axis);` 0.3mm (Z-axis) |
| Orientation Accuracy | < 10' (X & Y-axis); < 5' (Z-axis) |
| Wavefront Distortion | < l /4 @633nm |
| Scratch/Dig Code | 10/5 to MIL-O-13830A |
| Parallelism | < 10" |
| Flatness | l /8 @632.8nm |
| Chamfer | < 0.5 mm at 45o` 5o |
| AR-Coating | R < 0.2% @1064nm |
| Electrodes | Gold or Cr electrode on X-faces |
| Extinction Ratio | > 400:1 @633nm, (f 6mm beam) |
|
For electro-optic waveguide applications, the mostly used inorganic substrate is LiNbO3 crystal. |
|
| Standard Dimension | (1) 50x50x1 mm3 for X-cut, Y-cut, or Z-cut |
| (2) f 3"x1 mm3 for Y-cut or Z-cut | |
| Tolerance of Orientation | < 10' |
| Surface Finish | one surface polished to better than l /2 (with mount) and free from surface defects while observed by a 50X microscope, the other face fine ground |
|
|
|
|