Fiber lasers have revolutionized the manufacturing industry with their high efficiency and precision. However, they also pose potential hazards to operators and equipment. As a result, fiber laser protective windows have become essential components for laser safety in the industry.
Fiber laser protective windows are installed on the laser head to safeguard the surrounding environment and the operator's eyes from the laser beam. These windows are designed to absorb, reflect or scatter the laser energy, thus preventing any harmful effects.
Fiber lasers emit high-intensity laser beams that require specialized protective windows to enable safe operation in industrial settings. Whereas traditional laser technology employs solid-state materials (e.g., crystal, glass) to generate laser beams, fiber lasers use fiber optic cables to direct the laser and concentrate the laser beam’s intensity. Therefore, fiber laser protective windows ought to be designed with the high intensity of fiber laser beams in mind and resist damage and deterioration caused by the laser irradiation. Due to the unique characteristics of fiber lasers, fiber-optic protective windows typically have different characteristics and are made of varied materials.
The choice of materials used for fiber laser protective windows is crucial for their effectiveness. Several factors come into play, such as the wavelength and power output of the laser.
One of the popular materials used in protective windows is fused silica, also known as quartz glass. This material is highly resistant to thermal shock and has a high laser damage threshold. Fused silica's high transmittance in the near-infrared range of 1000-2000 nm makes it an ideal choice for fiber laser protective windows.
Sapphire is another material commonly used for fiber laser protective windows due to its excellent resistance to mechanical stress, high strength, and hardness. Even at higher temperatures, sapphire has exceptional stability and is highly transparent at wavelengths between 180 nm and 4,500 nm.
Another material used for protective windows is Zinc Selenide (ZnSe). This material has a high transmittance of up to 75%, making it an ideal choice for CO2 lasers operating near 10.6 µm.
For applications where the laser beam is of a higher power output, diamond windows may be used. Diamonds have an exceptional thermal conductivity and hardness, which makes them ideal for high-power fiber laser protective windows.
In addition to these materials, there are also composite materials, such as polycarbonate and acrylic, used for making protective windows. However, these materials have low thermal tolerance and transmittance properties, making them suitable only for lower-power applications.
Apart from the material used, the thickness of the protective window is also crucial. Thicker windows have higher absorption and scattering capabilities, but they may also cause laser beam divergence and reduce the laser's efficiency.
In conclusion, the material used for fiber laser protective windows plays a vital role in laser safety. Fused silica, sapphire, Zinc Selenide, and diamond windows are commonly used due to their high thermal and mechanical properties. Although composite materials may be used for lower-power applications, they are not ideal for high-power fiber lasers. Moreover, the thickness of the window should be carefully determined, depending on the laser's power output and application requirements.
Contact Person: Mrs. Nica Chow