High Temperature form BBO ( a -BaB 2 O 4 ) is a negative uniaxial crystal. It has large birefringence over the broad transparent range from 189 nm to 3500 nm. The physical, chemical, thermal and optical properties of a-BBO crystal are similar to those of b-BBO. However, the nonlinear optical properties of a-BBO crystal is vanished due to the centric symmetry with its crystal structure. It is not recommended to use for NLO processes.
Sellmeier equations: (l in mm) :
no2=2.7359+0.01878/(l2-0.01822)-0.01354l2 ne2=2.3753+0.01224/(l2-0.01667)-0.01516l2 |
Refractive Indices, Birefringence ( D n = n e - n o ) and Walk-off Angle at 45 o ( r ):
at 1.0642 m m n e = 1.5379, n o = 1.6579 Dn =-0.073282 r = -4.9532° at 0.5321 m m n e = 1.5534, n o = 1.6776 Dn =-0.075491 r = -5.0407° at 0.2660 m m n e = 1.6114, n o = 1.7617 Dn=-0. 089805 r = -5.6926° |
Surface Quality
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20/10 Scratch and Dig
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Beam Deviation
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<3 arc min.
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Optical Axis Orientation
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+/-0.5°
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Flatness
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<L /4 @ 632.8 nm
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Transmission Wavefront Distortion
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< L /2 @632.8 nm
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AR-coating
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R<0.5%
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