LBO

LBO

Lithium Triborate-LBO

Lithium Triborate (LBO) crystal (LiB₃O₅) has a wide transmittance band range (160-2600nm), high frequency doubling conversion efficiency, and its conversion efficiency is three times that of KDP crystal. Its light damage threshold is very high, light uniformity is very good, receiving angle is wide, mechanical properties are good, thermal shock resistance is strong, micro deliquescence, and nonlinear coefficient is large. It is one of the crystals with the best comprehensive performance among nonlinear crystals.

Description

Specifications

Dimension Tolerance	(W±0.1 mm) × (H±0.1 mm) × (L+0.2/-0.1 mm)
Clear Aperture	>90%
Surface Quality (Scratch/Dig)	10/5
Flatness	≤λ/8 @633 nm
Transmitted Wave-front Distortion	≤λ/8 @633 nm
Parallelism	≤10’’
Perpendicularity	≤10’
Angle Tolerance	±0.25 °
Chamfer	≤0.2 mm × 45 °
Chip	≤0.1 mm
Damage Threshold	>10 GW/cm²@1064 nm, 10 ns, 10 Hz (polished only)
	>1 GW/cm² @1064 nm, 10 ns, 10 Hz (AR-coated)
	>0.5 GW/cm²@532 nm, 10 ns, 10 Hz (AR-coated)
Coatings	Customized

Chemical and Structural Properties

Crystal Structure	Orthorhombic, Space group Pna21, Point group mm2
Lattice Parameter	a = 8.4473 Å, b = 7.3788 Å, c = 5.1395 Å, Z = 2
Melting Point	About 834 ℃
Mohs Hardness	6 Mohs
Density	2.47 g/cm³
Thermal Conductivity	3.5 W/m/K
Thermal Expansion Coefficients	α_x = 10.8 × 10^-5 /K, α_y = – 8.8 × 10^-5 /K, α_z = 3.4 × 10^-5 /K

Optical and Nonlinear Optical Properties

Transparency Range	160-2600 nm
SHG Phase Matchable Range	551-2600 nm (Type Ⅰ) 790-2150 nm (Type Ⅱ)
Therm-optic Coefficient (/℃, λ in μm)	dn_x / dT = – 9.3 ×10^-6 dn_y / dT = – 13.6 × 10^-6 dn_z / dT = (- 6.3 – 2.1 λ) × 10^-6
Absorption Coefficients	<0.1% /cm at 1064 nm, <0.3% /cm at 532 nm
Angle Acceptance	6.54 mrad·cm (Φ, Type Ⅰ, 1064 SHG) 15.27 mrad·cm (θ, Type Ⅱ, 1064 SHG)
Temperature Acceptance	4.7 ℃·cm (Type Ⅰ, 1064 SHG) 7.5 ℃·cm (Type Ⅱ, 1064 SHG)
Spectral Acceptance	1.0 nm·cm (Type Ⅰ, 1064 SHG) 1.3 nm·cm (Type Ⅱ, 1064 SHG)
Walk-off Angle	0.60 ° (Type Ⅰ, 1064 SHG) 0.12 ° (Type Ⅱ, 1064 SHG)
NLO Coefficients	d_eff (Ⅰ) = d₃₂ cosΦ (Type Ⅰ in XY plane) d_eff(Ⅰ) = d₃₁ cos2θ + d₃₂ sin2θ (Type Ⅰ in XZ plane) d_eff (Ⅱ) = d₃₁ cosθ (Type Ⅱ in YZ plane) d_eff (Ⅱ) = d₃₁ cos2θ + d₃₂sin2θ (Type Ⅱ in XZ plane)
Non-vanished NLO Susceptibilities	d₃₁= 1.05 ± 0.09 pm/V d₃₂= -0.98 ± 0.09 pm/V d₃₃= 0.05 ± 0.006 pm/V
Sellmeier Equations (λ in μm)	n_x²= 2.454140 + 0.011249 / (λ² – 0.011350) – 0.014591 λ² – 6.60 × 10^-5 λ⁴ n_y² = 2.539070 + 0.012711 / (λ² – 0.012523) – 0.018540 λ² + 2.00 × 10^-4 λ⁴ n_z² = 2.586179 + 0.013099 / (λ² – 0.011893) – 0.017968 λ² – 2.26 × 10^-4 λ⁴