BBO(Beta-Barium Borate) is one of the most commonly using NLO crystal for frequency conversion and Pockels cells. It combines very wide transparency, moderately high nonlinear coupling, high damage threshold, good chemical and mechanical properties. LNG Optics offers BBO elements with High optical homogeneity and High precision, especially Highly skilled in Ultra-thin BBO elements for ultrashort pulse lasers’ SHG and THG applications.
Features & Standard Specifications from LNG Optics:
Dimensions: Up to 25x25mm2
Thickness (Length): 0.01-25mm
Orientation angle accuracy: Δθ<0.2°Δφ<0.2°
Flatness: λ/10 @ 633nm
Transmitted Wavefront Distortion: λ/8 @ 633nm
Surface Quality: 10/5 Scratch/Dig
Clear Aperture: 90% central area
Parallelism: 20 arc seconds
Perpendicularity: 5 arc minutes
Coatings: Broadband Single Layer (MgF2), Broadband AR, Single & Dual band AR Coatings.
Cr/Au electrode coating for Pockels cell use BBO
Laser Damage Induced Threshold: 1GW/cm² for Polished only and Broadband Single Layer (MgF2)
Physical and Chemical Properties:
Chemical Formula: |
β-BaB2O4 |
Crystal Structure: |
Trigonal, Space group R3c |
Lattice Parameters (Å): |
a=b=12.532, c=12.717, Z=6 |
Melting point (°C): |
~1095 |
Mohs hardness: |
~4 |
Density (gram/cm3): |
3.85 |
Hygroscopic susceptibility: |
medium |
Thermal Conductivity (W/m/K): |
⊥c: 1.2, //c: 1.6 |
Thermal Expansion Coefficients (K-1): |
α11= 4 x 10-6, α33= 36 x 10-6 |
Resistivity (ohm•cm): |
>1011 |
Relative Dielectric Constant: |
εs11/ε0 = 6.7, εs33/ε0= 8.1 |
Optical and Nonlinear Properties:
Transparency Range: |
190-3500nm |
Phase Matching Range: |
Type I: 409.6-3500nm, Type II: 525-3500nm |
Electro-Optics Coefficients (pm/V): |
γ22 = 2.7 |
Thermo-Optic Coefficients (K-1): |
dno/dT = -16.6 x 10-6, dne/dT = -9.3 x 10-6 |
Sellmeier Equations (λ in μm): |
no2 = 2.7359 + 0.01878/(λ2 -0.01822) - 0.01354λ2 |
Effective Nonlinear Optical Coefficients: |
deff (I) = d31sinθ+(d11cos3φ-d22sin3φ)cosθ |
Non-vanished NLO susceptibilities: |
d11=5.8 x d36(KDP), d22=d31=0.05 x d11 |