Thin film coated optical fiber is a fiber optic cable with a thin film coating on its surface. This coating enhances the optical properties of the fiber, such as reflectivity or transmissivity, making it suitable for various applications in optics and photonics.
Gennerally, about 4% of incident light will be reflected at each surface of an uncoated optics fiber tip, the 4% of reflected light will be resulted as instability of the laser source and signal measurement. An anti-reflection coating could be applied to fiber tip to reduce the reflection to less than 0.1% to minimile the noise.
Anti-reflective coating, also called "AR coating", is a coating for glasses lenses that decreases reflective light.
An optical coating is composed of a combination of thin layers of materials such as oxides, metals, or rare earth materials. The performance of an optical coating is dependent on the number of layers, their thickness, and the refractive index difference between them.