Chinese brand BBO crystal for second frequency generation Application.
As a expert in nonlinear crystals, CRYSMIT offers high-quality BBO crystals at a competitive price.
Maximum Large size 20x20x10 mm3 for BBO coated crystals.
Ultrathin BBO (Thinnest 5um) crystals for Femtosecond Lasers.
A large quantity of BBO crystals in stock for fast delivery time.
Custom BBO nonlinear crystal size and advanced coating technology ensures high damage thresholds.
Offer sample , technical support and testing report for BBO nonlinear optical crystal for free.
Quantity discounts: for the same product, purchase 5 pieces for a 5% discount, and 10 pieces for a 10% discount.
CRYSMIT OPTICS is a professional supplier of “Chinese brand BBO crystals”. As a Chinese expert in BBO nonlinear crystals manufacturer, CRYSMIT offers high-quality BBO crystals at competitive prices. We offer BBO coated crystals with a maximum processing size of 20x20x10 mm3. Additionally, we are specialize in ultrathin BBO crystals with a minimum thickness of 5um designed for femtosecond lasers.
β-BaB2O4 (BBO, Beta barium borate) is a widely used nonlinear crystal for frequency conversion in the UV, visible and NIR. Crysmit's BBO Crystals feature:
Wide transmission from 190nm to 3500nm (Fig.1 and Fig.2)
Broad phase-matching range from 409.6nm to 3500nm
large birefringence and High optical homogeneity
BBO crystal second harmonic generation
Wide phase-matching range and Wide temperature bandwidth
Large nonlinear optical effects
A frequency multiplication factor six times higher than that of KDP crystals
High damage threshol
Fig.1. BBO crystal transmittance curve. Fig.2. BBO crystal transmittance curve in UV band.
Applications of BBO Crystals in the field of Nonlinear Crystals:
BBO for Second, Third, Fourth, and Fifth Harmonic Generation of Nd: YAG Lasers : Exceptional conversion efficiencies could be achieved using BBO crystals, which are greater than 70% (SHG), 60% for THG, 50% for 4thHG. BBO crystal is the best option for 213nm 5HG.BBO crystals excel in the ability to handle intracavity SHG of Nd:YAG lasers with high power densities to generate 532nm output. And 266nm output with a decent power level could be attained using a Brewster-angle-cut BBO crystal when pumping the Nd:YAG Laser with an SHG output of a mode-locked Nd:YLF laser. Because of a small acceptance angle and large angular walk off, good laser beam quality (small divergence, good mode condition, etc.) is the crucial factor for BBO to function better, tight focusing of laser beams is not recommended.
Femtosecond Lasers: For SHG and THG of Femtosecond Lasers, BBO also exhibits a great advantage over KDP and ADP crystals.
Dye Lasers:BBO crystal is an effective media for SHG of XeCl-laser pumped Dye lasers for giving output in the ultra-violet spectrum (205-310nm).
SHG/THG of Alexandrite Lasers and SHG/THG/FHG of Ti:Sapphire Lasers :SHG/THG of Alexandrite Lasers UV output in the region 360nm-390 nm and output in the region 244nm - 259 nm. SHG/THG/FHG of Ti:Sapphire Lasers could also be realized efficiently.
Intracavity SHG of Argon Doped Lasers and SHG of Copper-Vapor Lasers:Intracavity SHG of Argon Doped Lasers for UV and Deep-UV output, and SHG of Copper-Vapor Lasers for UV output.
Optical Parametric Oscillation (OPO) / Optical Parametric Amplification (OPA): Utilizing BBO crystals for optical parametric oscillation(OPO) and parametric optical amplification (OPA), one could easily obtain tunable output in a broad wavelength range (from the UV to IR). Common applications include: (1)OPO of 532nm pumped lasers for output ranging from 680 nm to 2400 nm and (2)OPO and OPA of 355nm Nd:YAG pumped lasers
CRYSMIT's BBO crystal Standard Speficication
Size | Crystal length from 0.005 mm to 25 mm and size up to 15x15x15 mm3 |
Dimension Tolerance | (W±0.1mm) x ( H±0.1mm) x (L+0.2mm/-0.1mm) |
Phase Matching Angle Tolerance | Δθ< 0.25°, Δφ< 0.25° |
Flatness | λ/10 @ 633nm |
Transmitted Wavefront Distortion | λ/8 @ 633nm |
Surface Quality | 10/5 Scratch/Dig per MIL-PRF-13830B |
Parallelism | < 20 arc seconds |
Perpendicularity | < 5 arc minutes |
Clear Aperture | 90% central area |
Edge Bevel | 0.15mm x 45°±5° |
AR Coating | R < 0.2% @ 1064nm, R < 0.5% @ 532nm |
Damage threshold | >1GW/cm2 for 1064nm, TEM00, 10ns, 10HZ (polished only) |
>0.5GW/cm2 for 1064nm, TEM00, 10ns, 10HZ (AR-coated) | |
>0.3GW/cm2 for 532nm, TEM00, 10ns, 10HZ (AR-coated) | |
Quality Warranty Period | One year under proper use. |
BBO Crystal Structure
Crystal Structure | Trigonal,Space Group R3c |
Lattice Parameter | a=b=12.532Å,c=12.717Å,Z=6 |
Melting Point | About 1095℃ |
Mohs Hardness | 4 |
Density | 3.85 g/cm3 |
Thermal Expansion Coefficients | α11=4 x 10-6/K; α33=36x 10-6/K |
Thermal Conductivity | ⊥c: 1.2W/m/K; //c: 1.6W/m/K |
BBO crystal properties
Transparency Range | 190-3500nm |
SHG Phase Matchable Range | 409.6-3500nm (Type I) 525-3500nm (Type II) |
Thermal-optic Coefficients (/℃) | dno/dT=-16.6x 10-6/℃ |
dne/dT=-9.3x 10-6/℃ | |
Absorption Coefficients | <0.1%/cm(at 1064nm) <1%/cm(at 532nm) |
Angle Acceptance | 0.8mrad·cm (θ, Type I, 1064 SHG) |
1.27mrad·cm (θ, Type II, 1064 SHG) | |
Temperature Acceptance | 55℃·cm |
Spectral Acceptance | 1.1nm·cm |
Walk-off Angle | 2.7° (Type I 1064 SHG) |
3.2° (Type II 1064 SHG) | |
NLO Coefficients | deff(I)=d31sinθ+(d11cos3Φ- d22 sin3Φ) cosθ |
deff (II)= (d11 sin3Φ + d22 cos3Φ) cos2θ | |
Non-vanished NLO susceptibilities | d11 = 5.8 x d36(KDP) |
d31 = 0.05 x d11 | |
d22 < 0.05 x d11 | |
Sellmeier Equations (λ in μm) | 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 |
Half-wave voltage | 7 KV (at 1064 nm,3x3x20mm3) |
Resistivity | >1011 ohm·cm |
Relative Dielectric Constant | εs11 / εo : 6.7 |
εs33 / εo : 8.1 | |
Tanδ<0.001 |
1. What is a china BBO Crystals ?
Chinese brand Barium borate (BaB2O4) was discovered and developed by Chen Chuangtian and others of the Fujian Institute of Research on the Structure of Matter (Fujian CASTECH Crystals), Chinese Academy of Sciences in1980. Barium borate (BaB2O4) is a type of borate mineral that can crystallize in two different forms: alpha-Barium borate (α-BBO) and beta-Barium borate (β-BBO):
α-Barium borate (α-BBO): This is a lower temperature phase that can be stable up to 925 degrees Celsius.α-Barium borate, α-BaB2O4, is an excellent birefringent crystal material with a very wide optical transmission window. With good mechanical properties, it is a suitable material for high power UV polarized optics. It is commonly used in Glan-Taylor prisms, Glan-Thompson prisms, Wollaston Polarizers, Spatial Compensators and Time Delay Compensators.
β-Barium borate (β-BBO or simply BBO): This is the high-temperature phase and can be stable at temperatures above 925 degrees Celsius. The β-BBO has exceptional nonlinear optical properties With Wide transmission from 190nm to 3500nm and Broad phase-matching range from 409.6nm to 3500nm and is widely used in many areas of physics and engineering.The β-BBO is the form that is typically referred to when discussing "BBO crystals" in the context of optics and laser technology.
2. How does a BBO crystal work ?
BBO (Beta Barium Borate) crystals are nonlinear optical crystals used primarily for frequency conversion, such as second harmonic generation (SHG). They work by exploiting nonlinear optical properties, allowing a high-intensity laser beam to interact with the crystal to produce light at different frequencies. When the wavevectors of the incident and generated waves are properly aligned within the BBO crystal (that is, phase matched), momentum and energy conservation are satisfied, enabling efficient nonlinear frequency conversion.
3. What is the applications of chinese BBO crystals ?
Lasers: BBO crystals can be used to change the frequency of laser light, allowing for the production of different colors. This is critical in applications like laser spectroscopy, medical laser devices, and laser displays.
Optical Parametric Oscillators (OPOs): BBO crystals are frequently used in OPOs, which generate a pair of waves with frequencies that are different from the pump frequency. OPOs are used in a variety of scientific and technological applications.
Quantum Communication and Computing: BBO crystals can be used to produce entangled photon pairs, a key component in quantum information technologies.
Telecommunications: In fiber-optic communications, BBO crystals can be used for wavelength conversion, allowing signals to be sent more efficiently over long distances.
Research and Development: BBO crystals are used in many scientific experiments, particularly those involving lasers and photonics, such as high-resolution microscopy, time-resolved spectroscopy, and ultrafast phenomena studies.
4. What are the types of BBO crystal directional cutting ?
The cutting type of a BBO crystal determines its phase-matching properties. Phase-matching refers to the alignment of the refractive index for different wavelengths, ensuring efficient light conversion. There are two primary cutting types – Type I and Type II.
Type I (e → o + o) Phase Matching: In Type I phase matching, both input waves (often referred to as the "pump" waves) have the same polarization. That is, they are either both ordinary waves (o-wave) or both extraordinary waves (e-wave). The generated wave can have the opposite type of polarization. This type of phase matching is typically used for second harmonic generation (SHG) and sum frequency generation (SFG).For instance, in second harmonic generation, two o-wave photons can combine to generate an e-wave photon with twice the frequency.
Type II (e → o + e) Phase Matching: In Type II phase matching, the input waves have different polarizations. One is an ordinary wave, and the other is an extraordinary wave. The polarization of the generated wave will then depend on the specifics of the interaction. This type of phase matching is commonly used for third harmonic generation (THG) and difference frequency generation (DFG).For example, in Third harmonic generation, an o-wave and an e-wave photon can combine to produce another e-wave or o-wave photon with twice the frequency.
CRYSMIT' s BBO Crystal orientation angle Theat and Phi (As Figure 1). When the Phi=90deg , BBO crystals are for Type I application. When the Phi=0deg , BBO crystals are for Type II application.
Figure 1
The choice between Type I and Type II phase matching will depend on the specific requirements of the application, including the wavelengths and polarizations of the light sources being used, and the desired properties of the output light.
5. How to identify BBO crystal tuning (adjusting) axis ?
In order to obtain maximum conversion efficience, adjust the angle is nomally used to reach phase-matching direction. The conversion efficience is very sensitive to adjust around m-axis which is called tuning axis of BBO crystals and It is normal to marked surface(As the Figure 2).
Figure 2
The marking the tuning axis of CRYSMIT' BBO crystal in the following two ways:
Figure 3 Figure 4
If it is a BBO crystal without holder, we will mark the tuning axis with a black dot on the side as the Figure 3.
If it is a BBO ctystals with holder, a white line across the middle of the holder indicates the tuning axis as Figure 4.
6. How to align a bbo crystal ?
Once you have identified the BBO crystal tuning axis, the next step is Aligning a BBO (Beta Barium Borate) crystal for optimal nonlinear frequency conversion (e.g., Second Harmonic Generation) requires precise adjustments to ensure maximum conversion efficiency.
Secure the BBO crystal in an adjustable mount that allows for angular rotation (typically around both horizontal and vertical axes). and Ensure your laser source is stable.
Direct the fundamental beam (the beam you want to convert) through the center of the BBO crystal. It should be perpendicular to the entrance and exit faces.
Slowly rotate the BBO crystal around the beam direction. This is the main "tuning" action.
While rotating, monitor the converted beam's intensity. For SHG, this would be the second harmonic generation.
As you notice the appearance of the second harmonic or the desired converted wavelength, fine-tune the angle to maximize its intensity. The position at which the intensity is highest is your optimal phase matching condition.
Tilt the crystal slightly in the vertical plane to check if this enhances the output. This adjustment ensures that the tuning axis is truly optimized in all dimensions.
Once you've achieved the maximum output intensity, lock the crystal mount to maintain this position.
7. How to choose the suitable china BBO crystals ?
Wavelength Range and Phase-matching range: BBO crystals have a wide transmission range from 190nm to 3500nm and a wide phase matching range from 409.6nm to 3500nm.
Phase Matching: Consider the phase matching conditions required by your application. This depends on the wavelengths and polarizations of the input and output light. You'll have to choose between Type I and Type II phase matching, depending on the application.
Size (Aperture): In order to choose a suitable size, the spot size of the laser must be considered. Usually, the effective size of BBO crystal needs to be 1-2mm larger than the laser spot. If in a tunable wavelength laser, it is also necessary to calculate the increase in crystal size due to wavelength tuning.
Thickness: Conversion efficiency, cost, and Group Velocities Mismatch are three important factors that determine crystal thickness.
Coating and Damage Threshold: Coating and Damage Threshold: Depending on your application, you might need a BBO crystal with a specific type of optical coating. P-coating has the advantages of wide band range, High Damage Threshold and low cost, but high loss due to reflectio. AR coating With Little loss due to reflection, but the film layer is thicker, the damage threshold is lower, and the firmness is slightly worse.
Cost: BBO crystals can vary in price depending on their size, quality, and any coatings they may have.
8. How to clean and Sotre BBO crystals ?
Preparation: Before you begin, make sure to wear gloves to prevent oils from your skin from contaminating the crystal surface. Prepare a clean, dust-free environment to work in.
Blow Off Dust: Use a can of compressed air or a clean, oil-free air gun to gently blow off any loose dust or debris from the crystal surface.
Solvent Cleaning: Dampen a lint-free cleaning cloth,absorbent cotton or lens tissue with a high-grade optical cleaning solvent. A common cleaning solution is a 50/50 mixture of ethanol and ether.
Cleaning Motion: Gently wipe the crystal surface with absorbent cotton. Use light pressure and clean in a circular motion, moving outward from the center. Avoid wiping back and forth, as this could grind any particles present into the surface.
Rinsing: For more thorough cleaning, the crystal can be rinsed with deionized or distilled water. Be aware that BBO crystals are hygroscopic and should not be soaked in water or left wet for extended periods.
Drying: Dry the crystal gently using dry, lint-free lens tissue, or let it air dry in a clean environment. You can also use compressed air to remove the excess water.
Inspection: After cleaning, inspect the crystal surface under a bright light to ensure all contaminants have been removed.
Storage : vacuum pack BBO crystals and Store BBO crystals in a clean, dry environment. And ensure the temperature and humidity stability of the environment.
9. Literature