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Available as boules, cut crystals or wafers, LiNbO3 single crystal possesses an attractive combination of piezoelectric and electro-optic properties which enable it to be widely used as frequency doublers, for Q-switches, waveguide substrates, surface acoustic wave (SAW) devices and so on. When doped with MgO, it has a greatly enhanced damage threshold.
Properties |
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| Crystal structure | Trigonal, space group R3c |
| Cell parameters | a=5.148Å, c=13.863Å |
| Density | 4.64 g/cm3 |
| Melting point | 1250°C |
| Curie point | 1140°C |
| Hardness | 5 Mohs |
| Extinction ratios | 1000:1 (optical crystal) |
| Birefringence gradient | 10-5cm-1(optical crystal) |
| SAW velocities | 3871 m/sec (zy-cut) |
| 3488 m/sec (yz-cut) | |
| 3889 m/sec (yx-cut 128°C) | |
| Absorption coefficient | ~0.1%/cm @ 1064nm |
| Solubility | insoluble in H2O |
| Relative dielectric constant | e11T/e0: 85; e33T/e0: 29.5 |
| Thermal expansion coefficients | ||a, 2.0 x 10-6 /K @ 25°C
||c, 2.2 x 10-6 /K @ 25°C |
| Thermal conductivity | 38 W/m/K @ 25°C |
Optical Properties |
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| Transparency range | 420 - 5200 nm |
| Refractive indices | ne=2.146, no=2.220 @ 1300nm |
| ne=2.156, no=2.232 @ 1064nm | |
| ne=2.203, no=2.286 @ 632.8nm | |
| Sellmeier equations | no2=4.9048+
0.11768/(l2-0.04750) -
0.027169l2 ne2=4.5820+ 0.099169/(l2-0.04443) - 0.02195l2 |
| Optical homogeneity | ~5x10-5 /cm |
| NLO coefficients | d33=34.4 pm/V |
| d31=d15=5.95 pm/V | |
| d22=3.07 pm/V | |
| Electro-optic coefficients |
g33T= 32 pm/V, g33S= 31 pm/V g31T= 10 pm/V, g31S= 8.6 pm/V g22T= 6.8 pm/V, g22S= 3.4 pm/V |
| For SHG of 1300nm | deff=5.7 pm/V or ~ 14.6 x d36 (KDP) |
| For OPO pumped at 1064 nm | deff=5.5 pm/V or ~ 13.6 x d36 (KDP) |
| For quasi-phase-matched structure | deff=17.6 pm/V or ~ 14.6 x d36 (KDP) |
Specification of Laser Grade LiNbO3 crystals |
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| Flatness | l/8 @633nm |
| Scratch/Dig | 20/10 or better |
| Transmitted wavefront distortion | better than l/4 @633nm |
| Dimension tolerance | Width ±0.01 x Height ±0.01 x Length ±0.02 mm |
| Clear aperture | over 90% central diameter |
| Parallelism | better than 20 arc sec. |
| Perpendicularity | 5 arc min. |
| Angle tolerance | Dq< 0.5o, Df< 0.5o |
| AR-coating | dual wave AR coating at 1064/532 nm on |
| both surfaces, with R<0.2% at 1064nm and | |
| R<0.5% at 532nm per surface. | |
Specification of SAW Substrates |
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| Size |
f3" (±0.01") x 0.5mm (±0.05mm) Other sizes available on request. |
| Orientation | x-cut, y-cut, z-cut, 127.86° y, 64° y, 47.5° y |
| Bow | 20-80µm |
| Surface finish | One surface mirror polished to Ra less than |
| 10Å, reversed side fine ground. | |
Integrated Optic Substrates: Custom-made to the required sizes and finish, surfaces polished to l/2; orientation tolerance is < 10".