α-BBO

α-BBO


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.

Basic 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

Capability

Common Specification
Diameter 40~50mm
Length 25~35mm
Surface Quality S/D 20-10
Beam deviation < 3 arc minutes
Optical axis orientation +/-0.5º
Flatness Better than Lambda/8 @633nm
Transmission Wavefront Distortion <Lambda/4 @633nm
Coating According to customer’s request