1. An infrared lens filter is an optical component used to focus, diverge, or control the propagation path of infrared light. Its operating principle is based on the law of refraction, similar to ordinary lenses, but it is specifically designed and optimized for the unique wavelength range of infrared light.

2. The wavelength range of infrared light is approximately 780nm to 1mm, which is longer than that of visible light. Infrared lenses are typically made from special materials such as germanium (Ge) and silicon (Si), which exhibit excellent optical properties in the infrared spectrum, with minimal absorption and scattering of infrared light, enabling efficient transmission of infrared light.

3. Its applications are extensive. In the field of security surveillance, infrared lenses can be used in infrared thermal imaging cameras to capture thermal radiation images of objects in low-light conditions, assisting surveillance personnel in identifying potential security threats. In military applications, infrared sights utilize infrared lenses to enable soldiers to clearly identify targets and aim their weapons in darkness. In industrial inspection, they can detect the thermal distribution of equipment and promptly identify potential faults. In the field of autonomous driving, infrared sensors combined with infrared lenses assist vehicles in perceiving their surroundings, identifying pedestrians, vehicles, and other objects, thereby enhancing driving safety.

4. The design and manufacturing of infrared lenses require high-precision technology and processes. Factors such as lens curvature, thickness, and surface quality must be considered to ensure good focusing and imaging performance for infrared light. Additionally, during use, it is important to protect the lens surface to prevent scratches, contamination, or other issues that could affect its optical performance.