





PRODUCTS
MESSAGES
α-BBO - Alpha-Barium Borate
Introduction
Alpha-Barium Borate (α-BaB2O4, α-BBO) is a negative uniaxial crystal which has large birefringence over a broad transparent range of 190 nm-3500 nm. α-BBO is an excellent crystal especially in UV and high power applications. The physical, chemical, thermal and optical properties of α-BBO crystal are similar to those of β-BBO. However, the nonlinear optical properties of α-BBO crystal are nonexistent due to the centrical symmetry of its crystal structure. α-BBO crystal is recommended for NLO processes.
CASTECH's birefringent crystal α-BBO is featured by
- High UV transmittance
- Large birefringence
- Low bulk absorption suitable for high power applications
- High damage threshold
- Stable physical and mechanical properties
Table 1. Basic Properties
Crystal Structure |
Trigonal |
Transparency Range |
190-3500 nm |
Density |
3.85 g/cm3 |
Hygroscopic Susceptibility |
Low |
Hardness |
4.5 Mohs |
Thermal Expansion Coefficients |
-9.3 × 10-6 /℃(C)-9.5 × 10-6 /℃(A) |
Damage Threshold |
1 GW/cm2 @1064 nm, 10 ns, 10 Hz (AR-coated) |
Refractive Indices |
no = 1.6776, ne = 1.5534, @532 nmno = 1.6579, ne = 1.5379, @1064 nm |
Sellmeier Equation (λ in μm) |
no2 = 2.7471 + 0.01878 / (λ2 - 0.01822) - 0.01354 λ2ne2 = 2.37153 + 0.01224 / (λ2 - 0.01667) - 0.01516 λ2 |
Table 2. Specifications of α-BBO
Size |
Aperture up to Φ50 mm and length up to 40 mm |
Surface Quality |
10/5 to MIL-PRF-13830B |
Flatness |
λ/4 @633 nm |
Optical Axis Orientation |
6 arc min |
Parallelism |
20 arc sec |
Clear Aperture |
> 90% |
Coating |
AR-coating or P-coating |
Mount |
Upon Customer's Specification |
Figure 1. Transparency Curve
Products
-
α-BBO - Alpha-Barium Borate
- α-BBO has a broad transparent range of 190 nm-3500 nm and high birefringence, and is widely used as Glan prisms and polarizing beam splitters for its high extinction ratio and UV transmission.
-
Introduction
Alpha-Barium Borate (α-BaB2O4, α-BBO) is a negative uniaxial crystal which has large birefringence over a broad transparent range of 190 nm-3500 nm. α-BBO is an excellent crystal especially in UV and high power applications. The physical, chemical, thermal and optical properties of α-BBO crystal are similar to those of β-BBO. However, the nonlinear optical properties of α-BBO crystal are nonexistent due to the centrical symmetry of its crystal structure. α-BBO crystal is recommended for NLO processes.
CASTECH's birefringent crystal α-BBO is featured by
- High UV transmittance
- Large birefringence
- Low bulk absorption suitable for high power applications
- High damage threshold
- Stable physical and mechanical properties
Table 1. Basic Properties
Crystal Structure |
Trigonal |
Transparency Range |
190-3500 nm |
Density |
3.85 g/cm3 |
Hygroscopic Susceptibility |
Low |
Hardness |
4.5 Mohs |
Thermal Expansion Coefficients |
-9.3 × 10-6 /℃(C)-9.5 × 10-6 /℃(A) |
Damage Threshold |
1 GW/cm2 @1064 nm, 10 ns, 10 Hz (AR-coated) |
Refractive Indices |
no = 1.6776, ne = 1.5534, @532 nmno = 1.6579, ne = 1.5379, @1064 nm |
Sellmeier Equation (λ in μm) |
no2 = 2.7471 + 0.01878 / (λ2 - 0.01822) - 0.01354 λ2ne2 = 2.37153 + 0.01224 / (λ2 - 0.01667) - 0.01516 λ2 |
Table 2. Specifications of α-BBO
Size |
Aperture up to Φ50 mm and length up to 40 mm |
Surface Quality |
10/5 to MIL-PRF-13830B |
Flatness |
λ/4 @633 nm |
Optical Axis Orientation |
6 arc min |
Parallelism |
20 arc sec |
Clear Aperture |
> 90% |
Coating |
AR-coating or P-coating |
Mount |
Upon Customer's Specification |
Figure 1. Transparency Curve