Uncooled Long-Wave Infrared (LWIR) Lens
  • Cooled IR Camera

Uncooled LWIR Lens | 8–14 µm Thermal Imaging Optics

Uncooled Long-Wave Infrared (LWIR) lenses are precision optical components designed for thermal imaging systems operating in the 8–14 µm wavelength range. These lenses are specifically matched with uncooled infrared detectors, eliminating the need for cryogenic cooling and enabling simpler, more compact, and cost-effective thermal imaging systems.

Compared with cooled infrared optics, uncooled LWIR lenses offer excellent robustness, lower system complexity, reduced power consumption, and high reliability, making them ideal for a wide range of commercial and industrial applications.

 

Optical Module Characteristics

  • Optimized for LWIR (8–14 µm) thermal imaging
  • Typically manufactured from Germanium (Ge) for high infrared transmittance
  • Designed for ambient-temperature operation with uncooled detectors
  • Rugged construction suitable for indoor and outdoor environments
  • No cooling-related vibration, noise, or maintenance requirements

 

Key Optical Parameters

  • Focal Length: Commonly 25 mm to 100 mm (custom options available)

  • Aperture (F-number): Wide apertures (e.g. F/1.0–F/1.2) for improved thermal sensitivity

  • Spectral Range: 8–14 µm (LWIR)

  • Transmittance: High transmittance optimized for long-wave infrared

  • Detector Compatibility:

    • Uncooled microbolometer detectors

    • Bolometric and pyroelectric detector arrays

  • Mount Type:

    • Standard C-mount

    • Custom mechanical mounts for specific camera platforms

 

Applications

Uncooled LWIR lenses are widely used in applications where cost efficiency, robustness, and reliability are more important than extreme sensitivity:

  • Building inspection and energy audits
  • HVAC system diagnostics
  • Industrial condition monitoring
  • Automotive night vision systems
  • Security and perimeter surveillance
  • Firefighting and emergency response
  • Environmental and infrastructure monitoring

 

How to Choose an Uncooled LWIR Lens

Selecting the right uncooled LWIR lens requires matching optical performance with your application needs:

1. Define the Application

Identify whether the lens will be used for security, industrial inspection, automotive systems, medical imaging, or environmental monitoring. Each application places different demands on field of view, resolution, and robustness.

2. Field of View & Focal Length

  • Short focal length: Wide field of view for close-range or situational awareness
  • Long focal length: Narrow field of view for longer-distance observation

Choose focal length based on target distance and scene coverage.

3. Lens Speed (F-Number)

A lower F-number (faster lens) allows more infrared energy to reach the detector, improving image quality—especially important for uncooled systems where sensitivity is inherently lower than cooled detectors.

4. Resolution Compatibility

Ensure the lens resolution matches or exceeds the detector resolution to avoid image degradation. This is critical for higher-resolution sensors (e.g. 640×512 or above).

5. Optical Materials & Coatings

Select lenses made from materials with high LWIR transmission, such as germanium, and equipped with LWIR anti-reflection coatings to maximize efficiency and contrast.

6. Detector & Mount Compatibility

Confirm compatibility with:

  • Detector size and pixel pitch
  • Camera mount (C-mount or custom)
  • Mechanical and optical interface requirements

7. Environmental Conditions

For outdoor or industrial use, consider resistance to:

  • Temperature fluctuations
  • Humidity and dust
  • Mechanical shock and vibration

8. Durability & Build Quality

High-quality mechanical design and optical finishing significantly improve long-term reliability and performance stability.

9. Budget Considerations

Uncooled LWIR lenses offer a strong performance-to-cost advantage. Balance budget against required resolution, aperture, and environmental robustness.