Calcium Fluoride (CaF2) Lenses
Broad Transmission Range: CaF2 lenses provide excellent transmission from deep UV (0.25μm) to MWIR (7μm), making them versatile for various optical applications.
Low Chromatic Dispersion: Their low chromatic dispersion ensures minimal distortion and high-quality imaging, essential for spectroscopic and imaging systems.
High Damage Threshold: CaF2 lenses can withstand high-intensity laser beams, making them ideal for excimer lasers and other high-power applications.
Low Absorption: Low absorption rates contribute to high efficiency and reduced thermal effects in laser systems.
Group Velocity Dispersion: The lowest GVD among IR materials makes CaF2 lenses suitable for femtosecond IR lasers, ensuring minimal pulse broadening.
Chemical Inertness and Mechanical Strength: CaF2 lenses are chemically inert and possess excellent mechanical strength, ensuring durability and longevity in harsh environments.
Applications: Spectroscopy, MWIR thermal imaging, excimer lasers, femtosecond IR lasers.
Calcium Fluoride (CaF2) Lenses are highly regarded for their exceptional optical properties, making them an excellent choice for a wide range of applications, from deep UV to MWIR (0.25μm to 7μm). Due to their high average transmission, low chromatic dispersion, and high damage thresholds, CaF2 lenses are particularly suitable for spectroscopic instruments, MWIR thermal imaging, excimer lasers, and femtosecond IR lasers.
Physical and Optical Properties:
| Materials | CaF2 crystals |
| Diameter Tolerance | +0.0/-0.2mm |
| Thickness Tolerance | +/-0.1mm |
| Surface Quality | 60/40 S/D |
| Chamfer | 0.1-0.3mmx45 degree |
| Coatings | AR/AR@3-5micro |
| Transmission Range | 0.13 to 10 μm |
| Refractive Index | 1.39908 at 5 μm (1) (2) |
| Reflection Loss | 5.4% at 5 μm |
| Absorption Coefficient | 7.8 x 10-4 cm-1 @ 2.7 μm |
| Reststrahlen Peak | 35 μm |
| dn/dT | -10.6 x 10-6/°C (3) |
| dn/dμ = 0 | 1.7 μm |
| Thermal Conductivity | 18.85 x 10-6/°C (5)(6) |
| Melting Point | 1360°C |
| Specific Heat Capacity | 854 J Kg-1 K-1 |
| Hardness | Knoop 158.3 (100) with 500g indenter |
| Density | 3.18 g/cc |
| Dielectric Constant | 6.76 at 1MHz (7) |
| Youngs Modulus (E) | 75.8 GPa (7) |
| Shear Modulus (G) | 33.77 GPa (7) |
| Bulk Modulus (K) | 82.71 GPa (7) |
| Elastic Coefficients | C11 = 164 C12 = 53 C44 = 33.7 (7) |
| Apparent Elastic Limit | 36.54 MPa |
| Poisson Ratio | 0.26 |
| Solubility | 0.0017g/100g water at 20°C |
| Molecular Weight | 78.08 |
| Class/Structure | Cubic (111) cleavage |
Advantages of Calcium Fluoride Lenses:
- Broad Transmission Range: CaF2 lenses provide excellent transmission from deep UV (0.25μm) to MWIR (7μm), making them versatile for various optical applications.
- Low Chromatic Dispersion: Their low chromatic dispersion ensures minimal distortion and high-quality imaging, essential for spectroscopic and imaging systems.
- High Damage Threshold: CaF2 lenses can withstand high-intensity laser beams, making them ideal for excimer lasers and other high-power applications.
- Low Absorption: Low absorption rates contribute to high efficiency and reduced thermal effects in laser systems.
- Group Velocity Dispersion: The lowest GVD among IR materials makes CaF2 lenses suitable for femtosecond IR lasers, ensuring minimal pulse broadening.
- Chemical Inertness and Mechanical Strength: CaF2 lenses are chemically inert and possess excellent mechanical strength, ensuring durability and longevity in harsh environments.
Considerations for Use:
- Handling and Cleaning: While CaF2 lenses are chemically inert and strong, they can be susceptible to mechanical stress and scratches, requiring careful handling and cleaning.
- Thermal Properties: Proper thermal management is essential in high-power applications to prevent thermal lensing and maintain optimal performance.
Applications:
- Spectroscopy: Utilized in spectroscopic instruments for accurate analysis across UV to MWIR wavelengths.
- MWIR Thermal Imaging: Integrated into thermal imaging systems for applications in defense, security, and industrial monitoring.
- Excimer Lasers: Ideal for high-power excimer lasers used in medical, industrial, and scientific applications.
- Femtosecond IR Lasers: Recommended for use in femtosecond IR laser systems due to their low GVD and high damage threshold.
Custom Solutions:
Kingwin Optics offers a range of custom Calcium Fluoride lenses tailored to specific needs. These lenses are available in various shapes and sizes, with specialized coatings to enhance their performance in specific applications. Kingwin Optics ensures high-quality and precision in their CaF2 lenses, making them suitable for demanding optical applications.
Calcium Fluoride lenses are versatile and high-performing optical components suitable for a wide range of applications, from spectroscopy to high-power laser systems. Their broad transmission range, low chromatic dispersion, high damage thresholds, and excellent mechanical properties make them ideal for use in MWIR thermal imaging, excimer lasers, and femtosecond IR lasers. With custom solutions from Kingwin Optics, CaF2 lenses can be tailored to meet specific requirements, ensuring optimal performance in various demanding environments.
