LBO Crystal
Lithium Tri-borate (LBO) is one of the most useful nonlinear optical material not just for its relatively large conversion coefficient - 3x that of KDP, but also for its excellent physical properties.
LBO crystal has broad optical transparency range from 160 to 2600nm. It excels in high power SHG with minimal thermal lensing as compared to KTP. Its large acceptance angle paired with small walk-off angle which reduces the beam quality requirement for source lasers.
FEATURES:
Broad transparency range from 160nm to 2600nm
Large effective SHG coefficient (about three times that of KDP);
High damage threshold;
Wide acceptance angle and small walk-off;
Type I and type II non-critical phase matching (NCPM) in a wide wavelength range;
Spectral NCPM near 1300nm.
Crystal Structure
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Chemical Formula
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LiB3O5
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Crystal Structure
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Orthorhombic, mm2
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Cell Parameters
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a = 8.4473, b = 7.3788Å, c = 5.1395Å, Z = 2
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Melting point
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834°C
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Optical homogeneity
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d n ~ 10-6/cm
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Mohs hardness
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6
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Density
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2.47 g/cm3
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Absorption coefficient
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< 0.1%/cm (at 1064nm and 532nm)
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Specific heat
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1.91J/cm3xK
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Hygroscopic susceptibility
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low
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Thermal expansion coefficients
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a, 4 x 10-6/K; c, 36 x 10-6/K
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Thermal conductivity
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^ c, 1.2 W/m/K; //c, 1.6 W/m/K
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Linear Optical Properties
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Transparency range
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160-2600nm
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Refractive indices:
at 1064nm
at 532nm at 355nm |
nx = 1.5656, ny = 1.5905, nz = 1.6055 (at 1064nm)
ne = 1.5785, no = 1.6065, nz = 1.6212
ne = 1.5971, no = 1.6275, nz = 1.6430 |
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Therm-optic coefficients
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dno/dT = -9.3 x 10-6/°C
dne/dT = -16.6 x 10-6/°C |
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Sellmeier Equations (l in mm)
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no2 (l) = 2.7359 - 0.01354l2+ 0.01878/(l2-0.01822)
ne2(l) = 2.3753 - 0.01516l2+ 0.01224/(l2-0.01667) |
Nonlinear Optical Properties
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Phase-matchable output wavelength
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554 - 2660nm (type I), 790 – 2150nm (type II)
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NLO coefficients
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d33 = 0.06; d32 = 1.2; d22 = 1.1
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Walk-off Angles(@ 1064nm)
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0.4° (Type I SHG), 0.3° (Type II SHG)
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Acceptance Angles(@1064nm) for SHG Type I
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9.6(mrad-cm) CPM at 25°C 248(mrad-cm) NCPM at 150°C
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Electro-optic coefficients
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g 11 = 2.7 pm/V, g 22, g31 < 0.1g11
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Conversion Efficiency
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>90% (1064 -> 532nm) Type I SHG
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Damage threshold
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45 GW/cm2(1 ns)@1064nm
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Capability:
1. Optical
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Specification
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Standard
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High Precision
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Dimensions
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Size: Up to 30x30mm2
Thickness: 0.1mm to 60mm
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Dimension Tolerance
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+/-0.1mm
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+/-0.01mm
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Wavefront Distortion
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λ/8
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λ/8
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Flatness
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λ/10
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λ/10
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Surface Quality
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10/5
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10/5
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Parallelism
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20’’
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10’’
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2. Coating
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Specificationg
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Reflection
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R<0.2%@1064nm, R<0.5%@532nm
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Damage Threshold
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>500MW/cm2
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