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LiNbO3 Crystal
LiNbO3 Crystal (LN Crystal, Lithium Niobate Crystal) has a lot super performance, such as ,Piezoelectric
Strain, electro-optic, voice-optic, nonlinear and so on. Due to its
large Electro-Optic (E-O) and Acousto-Optic (A-O) coefficients,
LiNbO3 crystal is the most commonly used material for Pockel Cells,
Q-switches and phase modulators, waveguide substrate, and surface
acoustic wave (SAW) wafers, etc.
LiNbO3 cystal is an most
imporant and versatile one. It is of nonlinear¡¯s properties, and the
nonlinear¡¯s coefficient is very large. Further more, it can enhance
their performance through some special way. Mixing the Mg, then the
LiNbO3 systal's laser damage threshold will be improved largely, as a
result, it promote the use of LiNbO3 crystal in in nonlinear
fields. Nd:Mg:LiNbO3 crystal, it can achieve the domino offect of
self-frequency.
Mixing the Fe, then the LiNbO3 cystal will
performace better in light storage in Electron-optic application. LiNbO3 crystal is a super material for light-wave transmit.Aslo, LiNbO3 crystal
is a good Piezoelectric Stain one, it can be used in high _low
frequency SAW filter or large power change machine. |
1. Basic Properties
Crystal Structure |
Trigonal, space group R3c |
| Cell Parameters |
a=b=5.148Å, c=13.863Å, Z=6 |
Melting Point |
1250¡ãC |
Curie Point |
1140¡ãC |
Mohs Hardness |
5 |
| Extinction Ratios |
1000:1 (optical crystal) |
| Birefringence Gradient |
10-5/cm (optical crystal) |
| SAW Velocities |
3871 m/sec (zy-cut)
3488 m/sec (yz-cut)
3889 m/sec (yx-cut 128¡ãC) |
Density |
4.64g/cm3 |
| Absorption Coefficient |
~ 0.1%/cm @ 1064 nm |
| Solubility |
insoluble in H2O |
| Relative Dielectric Constant |
¦ÅT11/¦Å0: 85
¦ÅT33/¦Å0: 29.5 |
Thermal Expansion Coefficient ( @ 25¡ãC) |
|| a, 2.0x10-6/K
|| c, 2.2x10-6/K |
Thermal Conductivity |
38 W /m /K @ 25¡ãC |
2. Linear
Optical Properties
Transparency Range
420-5200nm |
LiNbO3
Transparency Curve
|
Refractive Indices
ne=2.146, no = 2.220 @
1300 nm
ne= 2.156, no = 2.232 @ 1064 nm
ne= 2.203, no =
2.286 @ 632.8nm |
Optical Homogeneity:
~ 5 x 10-5 /cm |
Sellmeier Equations (l in mm):
no2 (¦Ë) =
4.9048+0.11768/(¦Ë2 - 0.04750) - 0.027169¦Ë2
ne2 (¦Ë) =
4.5820+0.099169/(¦Ë2 - 0.04443) -
0.021950¦Ë2 |
3. Nonlinear Optical Properties
NLO Coefficients |
d33 = 34.4 pm/V
d31 = d15 = 5.95 pm/V
d22 = 3.07 pm/V |
Efficiency NLO Coefficients |
deff =5.7 pm/V or ~14.6 x d36 (KDP) for
frequency doubling 1300 nm;
deff =5.3 pm/V or ~13.6 x d36 (KDP) for OPO pumped at 1064 nm;
deff =17.6 pm/V or ~45 x
d36 (KDP) for quasi-phase-matched structure. |
Electro-Optic Coefficients |
¦ÃT33 = 32 pm/V, ¦ÃS33 = 31 pm/V
¦ÃT31=10
pm/V, ¦ÃS31=8.6 pm/V
¦ÃT22 = 6.8 pm/V, ¦ÃS22=3.4
pm/V |
Half-Wave Voltage, DC
Electrical field || z,
light ¡Íz:
Electrical field || x or y, light || z: |
3.03 KV
4.02 KV
|
Damage Threshold |
100 MW/cm2 (10 ns,
1064nm) |
4. Standard Specifications of laser grade LiNbO3
crystals:
Transmitted Wavefront Distortion |
better than ¦Ë/4 @ 633nm |
Dimension Tolerance |
(W¡À0.1mm) x (H¡À0.1mm) x (L¡À0.2mm) |
Clear Aperture |
over 90% central diameter |
Flatness |
¦Ë/8 @ 633nm |
Surface Quality |
20 /10 Scratch/Dig |
Parallelism |
better than 20 arc sec |
Perpendicularity |
5 arc min |
Angle Tolerance |
¦¤¦È< 0.5¡ã, ¦¤¦Õ < 0.5¡ã |
AR-coating |
Per your
requirements |
LiNbO3 Typical Orientations:
► ¦È¡Ù0¡ã, ¦Õ=-90¡ã, For
SHG @ 1064nm Type I, fundamental wavelength range:
1.078¡ª3.5mm.
The following parameters are typically required
to specify when ordering:
► Sizes: Width x Height x Length
(mm)
► Phase matching angle: ¦È and ¦Õ
► Coating on S1&S2: Protective coating or reflectivity @ wavelength
Dimension Tolerance |
¡À0.1mm |
Thickness Tolerance |
¡À0.01mm |
Clear Aperture |
over 90% central diameter |
Surface Flatness |
10-15mm |
Surface Quality |
Ra<10Å |
Bow |
<20mm for ¦µ <60mm |
LiNbO3 wafer typical orientations:
X, Y, Z,
127.86¡ãY, 64¡ãY, 135¡ãY, 41¡ãY
LiNbO3 wafer typical diameter and
thickness:
¦Õ25.4mm, ¦Õ50.8mm, ¦Õ76.2mm, T=0.2~1.0mm
The
following parameters are typically required to specify when
ordering:
► Sizes: Diameter, thickness
►
Orientation: Normal to surface
► Surface finish: One surface or
double / surfaces polished
Note: Other specifications of LiNbO3
crystals and coatings are available upon your request. |
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