α-BBO(High Temperature form Barium Borate) crystal has large birefringence over 189-3500nm. All the properties of α-BBO are similar with β-BBOexcept for to be used in nonlinear optics due to its centric symmetry crystal structure. But α-BBO is an excellent birefringent crystal that would be used instead of Calcite, TiO₂or LiNbO₃, especially for high power and UV polarizers because of its deep UV transparency, good mechanical properties and high laser damage threshold. 

Chemical formula:α-BaB₂O₄

Transparency Range: 189-3500nm

Mohs hardness:4.5

Melting Point: 1095^oC

Density: 3.85 gram/cm³

Optical Homogeneity Δn <10^-6/cm

Hygroscopic Susceptibility: Low

Damage Threshold: 1GW/cm²@ 1064nm, 500MW/cm²@ 355nm

Refractive Indices, Birefringence (Δn=n_e-n_o)& Walk-off Angle @ 45^º(ρ):
@ 266nm n_o=1.7617, n_e=1.6114, Δn=-0.089805, ρ=-5.6926^º

@ 532nm n_o=1.6776, n_e=1.5534, Δn=-0.075491, ρ=-5.0407^º

@ 1064nm n_o=1.6579, n_e=1.5379, Δn=-0.073282, ρ=-4.9532^º

Sellmeier Equation(λ in μm):
n_o²= 2.7359 + 0.01878/(λ²-0.01822)-0.01354λ²
n_e²= 2.3753 + 0.01224/(λ²-0.01667)-0.01516λ²

 

Features and Standard specifications from LNG Optics:

Orientation accuracy: ± 12 arc minutes

Dimension tolerance: ± 0.2mm

Surface Quality: 10/5 S/D

Flatness: λ/8 @ 632.8nm

Parallelism: 30 arc seconds

Wedged angles accuracy: 3 arc minutes

Perpendicularity: 5 arc minutes

AR Coatings: single band, broadband

Mount: Upon request