Sapphire window panels, as a high-performance optical material, exhibit unique advantages in near-infrared applications (usually referring to the wavelength range of 780nm-2500nm) due to their excellent physical and chemical properties. The following will analyze the important value of sapphire window plates in the near-infrared field from the aspects of material properties, application scenarios, etc.

1、 Material Characteristics and Near Infrared Compatibility of Sapphire Window Plates

Sapphire is a single crystal aluminum oxide material with a Mohs hardness of 9, high thermal stability (melting point 2050 ℃), and chemical inertness. In terms of optical performance, sapphire has a transmittance of 85% -90% in the near-infrared band and a low absorption coefficient (<0.1%/cm). Compared with ordinary optical glass, sapphire's wide transmittance range (0.15-5.5 μ m) enables it to cover the core requirements of the near-infrared band, especially maintaining stable optical performance in high temperature or strong corrosive environments. For example, in laser systems, sapphire window plates can withstand prolonged exposure to high-power near-infrared lasers without experiencing thermal lensing effects.

2、 Near infrared application scenarios and technological implementation

1. Laser technology field

Near infrared lasers (such as 1064nm, 1550nm) are widely used in industrial processing, medical surgery, and military fields. Sapphire window plates, as output windows or protective lenses of laser cavities, can effectively isolate external pollutants while reducing laser energy loss. For example, in fiber laser cutting equipment, sapphire window plates can withstand high-temperature plasma sputtering, extending the service life of the equipment.

2. Infrared imaging and detection system

The near-infrared band is the core operating range of devices such as night vision goggles and thermal imagers. The high transmittance and scratch resistance of sapphire make it an ideal choice for protecting lenses.

3. Semiconductor Process and Testing

Near infrared light is commonly used for thin film thickness measurement and defect detection in the wafer manufacturing process. The chemical inertness of sapphire window plates can prevent reactions with process gases such as fluorides, ensuring detection accuracy. In addition, its low thermal expansion coefficient (5.3 × 10 ??/K) can reduce the impact of temperature fluctuations on optical systems.

4. Medical equipment

When near-infrared spectroscopy (NIRS) technology is used for non-invasive blood glucose monitoring or cerebral oxygenation detection, sapphire window plates can serve as sensor contact windows, combining biocompatibility and high transparency.

The application of sapphire window panels in the near-infrared band fully reflects the law that "materials determine technological boundaries". With the advancement of processing technology and the growth of interdisciplinary demand, as an optical component, it will continue to unleash its potential in manufacturing, defense technology, and life sciences.