BBO Crystals

Physical and optical propertie

Chemical formula β-BaB2O4
Crystal structure Rhomboedral, 3m
Lattice parameters a=12,532 Å, c=12,717 Å
Optical symmetry Negative uniaxial (no > ne)
Density 3,85 g/cm3
Mohs hardness 4 - 4,5
Transparency range 188 nm - 5,2 µm, reasonable from 3 µm to 5,2 µm for thin crystals (few ten of µm)
Dispersion equations @188 nm - 5.2 µm (λ in µm) no2=1+0.90291 λ2/(λ2-0,003926)+0.83155 λ2/(λ2-0.018786)+0.76536 λ2/(λ2-60.01);
ne2=1+1.151075 λ2/(λ2-0.007142)+0.21803 λ2/(λ2-0.02259)+ 0,656 λ2/(λ2-263)
Refractive indices @1064 nm no = 1,6551; ne = 1,5426

Standard specifications

Orientation accuracy <30 arcmin
Clear aperture >90%
Face dimensions tolerance +0/-0.1 mm
Length tolerance ±0.1 mm
Parallelism error <20 arcsec
Perpendicularity error <5 arcmin
Protective chamfers <0.1 mm at 45˚
Surface quality 10-5 S-D
Wavefront distortion λ/8@632,8 nm
Coatings Low dispersion protective coatings or antireflective coatings on both sides
Laser induced damage threshold >500MW/cm2@1064 nm, 10ns
Mount Mounted in D25,4 mm black anodized aluminum mount