BBO Nonlinear crystal Beta-Barium Borate Crystal
- β-BBO, discovered by FIRSM of Chinese Academy of Sciences, now is manufactured and marketed by AOST. Besides as a NLO crystal for SHG and FOHG, it’s also usd in OPO and ultrashort-pulse lasers.
Main applications:
- Harmonic generation (up to fifth) of pulsed Nd-doped crystal-based lasers.
- Frequency doubling, a tripling of pulsed Ti:sapphire, Yb-doped, dye lasers.
- Characterization of ultrashort laser pulses by FROG, XFROG, SPIDER, dispersion scan, chirp scan methods.
- OPA andOPO.
- Pockels’ Cell
Advantages:
- Broad phase match range from 409.6 nm to 3500 nm;
- Wide transmission region from 190 nm to 3500 nm;
- Large effective second-harmonic-generation (SHG) coefficient;
- High damage threshold;
- High optical homogeneity with δn ≈10-6/cm;
- Wide temperature-bandwidth of about 55℃.
Optical and Nonlinear properties of BBO crystal
| Transparency Range | 190-3500nm |
| SHG Phase Matchable Range | 409.6-3500nm (Type I) 525-3500nm (Type II) |
| Therm-optic Coefficient (/℃, λ in μm) | dno/dT=-16.6x 10-6/℃ dne/dT=-9.3x 10-6/℃ |
| Absorption Coefficients | <0.1%/cm(at 1064nm) <1%/cm(at 532nm) |
| Angle Acceptance | 0.8mrad·cm (θ, Type I, 1064 SHG) 1.27mrad·cm (θ, Type II, 1064 SHG) |
| Temperature Acceptance | 55℃·cm |
| Spectral Acceptance | 1.1nm·cm |
| Walk-off Angle | 2.7° (Type I 1064 SHG) 3.2° (Type II 1064 SHG) |
| NLO Coefficients | deff(I)=d31sinθ+(d11cos3Φ- d22 sin3Φ) cosθq deff (II)= (d11 sin3Φ + d22 cos3Φ) cos2θ |
| Non-vanished NLO susceptibilities | d11 = 5.8 x d36(KDP) d31 = 0.05 x d11 d22 < 0.05 x d11 |
| Sellmeier Equations (λ in μm) | no2=2.7359+0.01878/(λ2-0.01822)-0.01354λ2 ne2=2.3753+0.01224/(λ2-0.01667)-0.01516λ2 |
| Electro-optic coefficients | γ22 = 2.7 pm/V |
| Half-wave voltage | 7 KV (at 1064 nm,3x3x20mm3) |
| Resistivity | >1011 ohm·cm |
| Relative Dielectric Constant | εs11 / εo : 6.7 εs33 / εo : 8.1 Tanδ<0.001< span=””> |
Physical properties of BBO crystal
| Crystal Structure | Trigonal，Space Group R3c |
| Lattice Parameter | a=b=12.532Å,c=12.717Å,Z=6 |
| Melting Point | About 1095℃ |
| Mohs Hardness | 4 |
| Density | 3.85 g/cm3 |
| Refractive indices | no = 1,6551; ne = 1,5426 |
| Thermal Conductivity | ⊥c: 1.2W/m/K; //c: 1.6W/m/K |
| Thermal Expansion Coefficients | α11=4 x 10-6/K; α33=36x 10-6/K |
BBO specifications:
| Tolerance of cutting angle | △θ≤±0.25°,△φ≤±0.25° |
| Tolerance of dimension | Dimension+0/-0.1 mm，L：±0.1mm |
| Flatness | λ/10 @ 632.8nm |
| Wavefront distortion | λ/8@ 632.8nm |
| Surface quality | 10/5 per MIL-O-13830A |
| Parallelism | 20″ |
| Perpendicularity | 15′ |
| Clear Aperture: | > 90% |
| Chamfer: | < 0.1 mm @ 45° |
| Size | Upon customer request |
| Coating | AR/PR coating upon customer’s request |
| Damage Threshold | 750MW/CM2 at 1064nm, TEM00, 10ns, 10Hz |
| Quality Warranty Period | One year under proper use |
