Barium β-borate (β-BaB2O4, BBO) crystals are nonlinear optical materials with many unique properties, such as a wide range of transparency and phase matching, and thus present appealing opportunities for a number of nonlinear optical applications. The transparency range of BBO crystals is 188 nm to 5.2 μm, and practically the full transparency range is covered by the phase matching range. BBO crystals have the highest UV nonlinearity of any conventional nonlinear crystal.
BBO crystals provide appealing solutions for a range of nonlinear optical applications, including OPO, OPA, OPCPA, etc. because of their distinctive features. Alfa Chemistry, a nonlinear crystal specialist, will carefully and patiently walk customers through the online ordering process for BBO nonlinear crystals.
Advantages of BBO Crystals
BBO crystals combine numerous distinctive properties of nonlinear optical crystals with distinct benefits to produce exceptional performance. A wide range of transparency and phase matching (409.6 nm to 3500 nm), a large nonlinear coefficient (roughly 6 times that of KDP crystals), a wide temperature matching range, a high damage threshold, a large matching angle, and excellent optical uniformity (dn » 10-6/cm) are just a few of the characteristics of nonlinear BBO crystals offered by Alfa Chemistry.
BBO crystals are ideal for frequency conversion of high or average power laser light because of their broad thermal acceptance range, high damage threshold, and low absorption BBO.
Fig 1. Three transverse SHG intensity images of a BBO crystal, measured at the focal plane (z = 0) and 7 μm above and below the focal plane. (Hu C, et al. 2020)
Properties of BBO Crystals
| Physical Properties | |
|---|---|
| Crystal Structure | Trigonal, Space Group R3c |
| Lattice Parameter | a=b=12.532Å, c=12.717Å, Z=6 |
| Density | 3.85 g/cm3 |
| Melting Point | ~ 1095 ℃ |
| Mohs Hardness | 4 |
| Thermal Conductivity | ⊥c: 1.2 W/m/K; //c: 1.6 W/m/K |
| Thermal Expansion Coefficients | α11=4 x 10-6/K; α33=36 x 10-6/K |
| Refractive Indices | no = 1.6551; ne = 1.5426 |
| Optical and Nonlinear Properties | |
| Transparency Range | 190 ~ 3500 nm |
| Absorption Coefficients | <0.1%/cm at 1064 nm; <1%/cm at 532 nm |
| Therm-optic Coefficient | dno/dT=-16.6X10-6/℃; dne/dT=-9.3X10-6/℃ |
| NLO Coefficients | deff(I)=d31sinθ+(d11cos3Φ- d22 sin3Φ) cosθq deff(II)= (d11 sin3Φ + d22 cos3Φ) cos2θ |
| Sellmeier Equations | no2=2.7359+0.01878/(λ2-0.01822)-0.01354λ2 ne2=2.3753+0.01224/(λ2-0.01667)-0.01516λ2 |
| Electro-optic Coefficients | γ22 = 2.7 pm/V |
| Resistivity | >1011 ohm·cm |
| Alfa Chemistry offers BBO specification | |
| Dimension | Upon customer request |
| Dimension Tolerance | Dimension+0/-0.1 mm, L±0.1mm |
| Cutting Angle Tolerance | △θ≤±0.25°,△φ≤±0.25° |
| Flatness | λ/10 @ 632.8nm |
| Surface Quality | 10/5 per MIL-O-13830A |
| Clear Aperture | > 90% |
| Damage Threshold | 750MW/cm2 at 1064nm, TEM00, 10ns, 10Hz |
| Coating | AR/HR coating upon customer's request |
| Quality Warranty Period | One year under proper use |
Why Choose Alfa Chemistry?
According to customer specifications, Alfa Chemistry can create BBO crystals with dimensions of up to 15mm*15mm*15mm and lengths ranging from 0.05mm to 25mm. Our custom BBO crystals are renowned for their great quality and reasonable price by customers from all over the world because to our many years of crystal growth experience.
To develop BBO crystals, we employ flux growth techniques. To ensure that each custom crystal will meet the requirements of the customer and function effectively in the laser system, high quality starting materials are used for crystal growth, and strict quality control is performed on absorption, scattering loss, volume loss, wavefront distortion, inclusions, and all other required processing specifications of our BBO's.
If you need technical advice, please contact our technical team to learn more about our high-quality services.
Reference
- Hu C, et al. (2020). "Harmonic optical tomography of nonlinear structures." Nature Photonics. 14: 564-569.