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Beta Barium Borate ( β-BaB2O4 or BBO)
1.
Application:
* Frequency Doubling (SHG) of Nd-doped Lasers for Green/Red Output.
* Frequency Mixing (SFM) of Nd Laser and Diode Laser for Blue Output.
* Parametric Sources ( OPA and OPO) for 0.6mm-4.5mm Tunable Output.
* E-O Modulators, Optical Switches.
* Optical Waveguides for Integrated NLO and E-O Devices.
* Frequency-doubling of Argom ion, Cu-capor and Ruby lasers.
2.
Advantages:
Broad phase-matchable range from 409.6 nm to 3500 nm;
Wide transmission region from 190 nm to 3500 nm;
Large effective SHG coefficient about 6 times greater than that of KDP crystal;
High damage threshold of 10 GW/cm2 for 100 ps pulse-width at 1064 nm;
Good Mechanical and physical properties
Wide temperature-bandwidth of about 55°C(for type I SHG 1064nm)
3.
Physical and Chemical Properties:
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Crystal Structure |
Trigonal, space group R3c |
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Lattice Parameters |
a=b=1.253nm, c=1.272nm |
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Density |
3.85 g/cm3 |
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Melting Point |
1095±5°C |
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Phase transition temperature |
925±5°C |
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Mohs Hardness |
4.5~5 |
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Temperature stability |
8 x KDP |
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FWHM of phase matched SHG |
55°C |
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Absorption coefficient @1064nm |
<0.1%/cm3 |
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Hygroscopic susceptibility |
Low |
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Resistivity |
>100 G ohm/cm |
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Thermal expansion coefficients (25?900癈) |
a, 4 x 10-6/K; c, 36 x 10-6/K |
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Thermal conductivity |
⊥c,1.2 W/m/K; //c,1.6 W/m/K |
4.
Linear Optical Properties:
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Transmitting range: |
189~3500 nm |
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Wavelengh: |
at 1064 nm |
at 532 nm |
at 266 |
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Refractive indices: |
ne=1.5425, |
ne = 1.5555, |
ne = 1.6146, |
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no=1.6551, |
no=1.6749, |
no = 1.7571, |
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Therm-optic coefficients: |
dne/dT = -16.6 x 10-6/K |
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dn0/dT = -9.3 x 10-6/K |
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Sellmeier equations: |
Ne2 = 2.7359+0.01878/(λ2-0.01822)-0.01354λ2 |
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No2 =2.3753+0.01224 / (λ2-0.01667)-0.01516λ2 |
5.
Nonlinear Optical properties:
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Phase matching output wavelenghs: |
189 - 1750nm |
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Nonlinear Coefficients:
where θ and φ are polar
coordinatesreferring to
z(=c) and x(=a),
respectively |
d11 = 5.8 x d36(KDP) |
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d31 = 0.05 X d11 |
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d22 <0.05 x d11 |
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Type I: deff = d31 sinθ+(d11 cos3φ-d22 sin3φ)cosθ |
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Type II:deff = (d11 sin3φ+ d22 cos3φ)cosθ cosθ |
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Electro-optic coefficients: |
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r11 |
2.7pm/v |
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r22 |
< 0.1 r11 |
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r31 |
< 0.1 r11 |
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Half-wave voltage:(at 1064nm) |
48 KV |
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Optical damage threshold: |
at 1064 nm |
at 532 nm |
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5GW/cm2(10s),10GW/cm2(1.3s) |
1GW/cm2(10s),7GW/cm2(250s) |
Standard size:4x4x(5-12)mm,6x6(5-12)mm,7x9x14mm,12x12x4mm
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