α-BBO
Description:
High temperature phase of α-BBO Crystal (BaB2O4) is one of the excellent birefringent crystals. It is characterized by large birefringent coefficient and wide transmission window ranged from 189nm to 3500nm. Due to its high chemical stability and medium hardness, α-BBO is fabricated easily into many kinds of optical components.
Physical and optical properties:
| Transparency range | 189-3500nm |
| Density | 3.85g/cm3 |
| Thermo-optic coefficients | dno / dT = -9.3 X 10-6/℃, dne / dT = -16.6.3 X 10-6 /℃ |
| Optical homogeneity | Δn≈10-6/cm |
| Damage threshold | 1 GW/cm2@1064nm; 500 MW/cm2@532nm |
| Hygroscopic susceptibility | Low |
| Thermal expansion coefficients | aa = 4 X 10-6 / K, ac = 4 X 10-6 / K |
| (25ºC-900ºC) | |
| Linear absorption coefficients | α<0.005cm-1 from 300nm to 2300nm |
| Refractive indices, birefringence | ne=1.58462, no=1.65790,Δn=-0.073282; ρ=-4.9532º @1064nm |
| (Δn=ne-no) and walk-off angle at 45º | ne=1.60206,no=1.67755,Δn=-0.075491; ρ=-5.0407º @ 532nm |
| ne=1.67190,no=1.76171,Δn=-0.089805; ρ=-5.6926º @ 266nm |
Specifications:
| Diameter | 40~50mm |
| Length | 25~35mm |
| Surface Quality | 20/10 Scratch/Dig |
| Beam deviation | < 3 arc min |
| Optical axis orientation | +/-0.5º |
| Flatness | Better than λ/8 @633nm |
| Transmission wave front distortion | <λ/4 @633nm |
| Coating | upon customer's request |