Barium borate (BBO) is a versatile nonlinear crystal, suitable for use in harmonic generation operations, optical parametric oscillators, and in electro-optical applications from the near infrared to the deep ultraviolet. Among BBO’s attractive features are it’s large nonlinear coefficients, high threshold for laser damage, and low thermo-optic coefficient.
At Inrad Optics, high quality BBO single crystals are grown using a top seeded solution growth technique. Our in-house growth, fabrication, and finishing provide unparalleled material traceability and process consistency.
Popular applications of BBO include generating the third, fourth, and fifth harmonics of Nd:YAG lasers (355nm, 266nm, and 213nm respectively), the second and third harmonics of Ti:Sapphire amplifiers (400nm and 266.7nm), and a variety of sum frequency mixing schemes using dye lasers. BBO can be used in OPO configurations to generate tunable output in the visible to near infrared range. BBO is also well suited to Q-switching and other electro-optical applications in high power UV laser systems.
| Material Properties | |
| Chemical Formula | ß - Ba2BO4 |
| Crystal Symmetry and Class | trigonal, R3c Point Group 3m |
| Lattice Parameters | a = 12.547 Å |
| c = 12.736 Å | |
| Density | 3.85 g/cm3 |
| Mohs Hardness | 4.5 |
| Optical Class | Uniaxial negative |
| Transmission Range | 0.198 μm – 2.6 μm |
| Thermal Conductivity | κ = 0.08 W/m∙K ( ⊥c ) |
| κ = 0.8 W/m∙K ( ∥ c ) | |
| Thermal Expansion for T = 293 - 1173 K |
α11 = 4 x 10-6 /K α33 = 36 x 10-6 /K |
| Electro Optic Coefficients @ 0.633 μm T: unclamped |
r22S = 2.1 pm/V r22T = 2.5 pm/V |
Dimensions
We fabricate and polish BBO crystals in a wide range of standard and custom sizes and orientations. Available lengths range from 50 µm for short-pulse work to 25 mm for nanosecond OPO/OPA use. Crystals are oriented in a double crystal x-ray spectrometer and are accurate to ± 5 minutes.
Finishing
- BBO crystals are available with a dielectric coating to protect polished surfaces from fogging due to ambient moisture. AR coatings also reduce reflections from polished surfaces, improving transmission quality for all wavelengths.
- Electrodes for Q-switching
- Cut at Brewster’s angle
- Ring mounts compatible with standard optomechanics
Configuration Options
| Designation | Angle, θ | Operation | Input | Output |
| “0” | 68.5° | SHG | 418-464 nm | 209-232 nm |
| THG | (600-665 nm) + (300-331 nm) | 200-220 nm | ||
| “1” | 53.2° | SHG | 454-560 nm | 209-232 nm |
| THG | (651-800 nm) + 325-400 nm) | 217-266 nm | ||
| “2” | 37.4° | SHG | 542-820 nm | 271-410 nm |
| THG | (774-1165 nm) + (387-582 nm) | 258-388 nm | ||
| “A” | 78° | SHG | 410-433 nm | 205-216 nm |
| THG | (594-620 nm) + (297-310 nm) | 198-206 nm | ||
| “B” | 55° | SHG | 448-543 nm | 224-271 nm |
| THG | (642-775 nm) + (321-358 nm) | 214-258 nm | ||
| “C” | 65° | SHG | 423-480 nm | 211-240 nm |
| THG | (608-687 nm) + (304-343 nm) | 203-229 nm | ||
| “TSS” | 28.7° | SHG | 636-1000 nm | 318-500 nm |
| THG | (906-2100 nm) + (453-1050 nm) | 302-700 nm | ||
| “TST” | 44° | SHG | 496-675 nm | 248-337 nm |
| THG | (710-960 nm) + (355-480 nm) | 237-320 nm | ||
| “OPO1” | 36.6° | SHG | 549-844 nm | 275-422 nm |
| THG | (784-1200 nm) + (392-600 nm) | 262-400 nm | ||
| SFM | 1064 nm + (510-567 nm) | 345-370 nm | ||
| “OPO2” | 57.5° | SHG | 440-525 nm | 220-262 nm |
| THG | (632-750 nm) + (316-375 nm) | 211-250 nm | ||
| “M1” | 50.2° | SFM | 1064 nm + (243-340 nm) | 198-257 nm |
| “DGN” | 31° | SFM | 1064 nm + (380-980 nm) | 280-510 nm |
| “IDLR” | 20° | SHG | 1380-1460 nm | 690-730 nm |
| “OPO3” | 30° | OPO | 355 nm | 410-2000 nm |
| “SHG” | 22.8° | SHG | 1064 nm | 532 nm |
| “THG” | 31.3° | THG | 1064 nm + 532 nm | 355 nm |
| “4HG” | 47.6° | 4HG | 532 nm | 266 nm |
| — | 22° | SHG | 1550 nm | 775 nm |