Germanium (Ge) Lenses
Thermal Imaging: Used in thermal cameras and imaging systems for security, surveillance, and industrial inspections.
IR Spectroscopy: Essential for spectroscopic instruments used in chemical analysis and material characterization.
CO₂ Laser Optics: Commonly used in high-power CO₂ laser systems due to their excellent transmission at 10.6 µm.
Night Vision Systems: Integrated into night vision devices to enhance infrared sensitivity and image clarity.
Defense and Security Optics: Applied in various military and security equipment for infrared detection and imaging.
Applications: Thermal imaging, IR spectroscopy, CO₂ laser optics, night vision systems, defense and security optics.
Germanium (Ge) lenses are critical components in infrared (IR) imaging systems due to their excellent transmission properties across a wide spectral range and their mechanical robustness. These lenses are optimized for use in the LWIR (8-12µm) and MWIR (3-5µm) ranges, providing high performance in demanding applications.
Advantages of Germanium Lenses:
- Wide Transmission Range: Germanium lenses transmit efficiently from 2 µm to 16 µm, covering both MWIR and LWIR spectral ranges, making them ideal for various IR applications.
- High Refractive Index: The high refractive index (4.002 at 10.6 µm) ensures excellent light collection and bending strength, enhancing the efficiency of optical systems.
- Minimal Chromatic Aberration: Low optical dispersion results in minimal chromatic aberration, providing clear and accurate transmission of optical signals.
- Mechanical Robustness: With a Knoop hardness of 780 kg/mm², Germanium lenses are durable and resistant to mechanical damage. Coatings like diamond or DLC can further enhance their toughness.
- Customizability: Kingwin Optics offers custom Germanium lenses in various shapes, including plano-convex, plano-concave, double convex, double concave, and meniscus lenses. Both spherical and aspherical surfaces are available, with dimensions up to 300 mm.
Coating Options:
- Anti-Reflection (AR): Enhances transmission by reducing surface reflections.
- Broad Band Anti-Reflection (BBAR): Provides enhanced transmission over a wide spectral range.
- Diamond-Like Carbon (DLC): Adds a hard, durable layer for increased resistance to scratches and harsh environments.
Applications:
- Thermal Imaging: Used in thermal cameras and imaging systems for security, surveillance, and industrial inspections.
- IR Spectroscopy: Essential for spectroscopic instruments in chemical analysis and material characterization.
- CO₂ Laser Optics: Commonly used in high-power CO₂ laser systems due to their excellent transmission at 10.6 µm.
- Night Vision Systems: Integrated into night vision devices to enhance infrared sensitivity and image clarity.
- Defense and Security Optics: Applied in military and security equipment for infrared detection and imaging.
Physical and Optical Properties:
| Materials | Optical grade germanium single crystals |
| Diameter Tolerance | -0.01/-0.03mm |
| Thickness Tolerance | +/-0.03mm |
| Surface Quality | 60/40 S/D |
| Chamfer | 0.1-0.3mmx45 degree |
| Transmission Range | 1.8 to 23 μm |
| Refractive Index | 4.0026 at 11 μm |
| Reflection Loss | 53% at 11 μm (2 surfaces) |
| Absorption Coefficient | <0.027 cm-1@ 10.6 μm |
| Reststrahlen Peak | n/a |
| dn/dT | 396 x 10-6 /°C |
| dn/dμ = 0 | Almost constant |
| Thermal Conductivity | 58.61 W m-1 K-1 at 293K |
| Melting Point | 936 °C |
| Dielectric Constant | 16.6 at 9.37 GHz at 300K |
| Thermal Expansion | 6.1 x 10-6/°C at 298K |
| Hardness | Knoop 780 |
| Specific Heat Capacity | 310 J Kg-1 K-1 |
| Density | 5.33 g/cc |
| Bandgap Energy | 0.67 eV |
| Youngs Modulus (E) | 102.7 GPa |
| Shear Modulus (G) | 67 GPa |
| Bulk Modulus (K) | 77.2 GPa |
| Elastic Coefficients | C11=129; C12=48.3; C44=67.1 |
| Apparent Elastic Limit | 89.6 MPa (13000 psi) |
| Poisson Ratio | 0.28 |
| Solubility | Insoluble in water |
| Molecular Weight | 72.59 |
| Class/Structure | Cubic Diamond, Fd3m |
Custom Solutions:
Germanium lenses provide superior performance in infrared optics due to their wide transmission range, high refractive index, and mechanical robustness. They are ideal for applications in thermal imaging, IR spectroscopy, laser optics, and more, offering versatility and reliability in demanding environments.
Kingwin Optics offers a wide range of custom Germanium lenses tailored to specific application requirements. These lenses can be designed with various shapes, dimensions, and coatings to ensure optimal performance in infrared applications.
