Graded-index fiber is a type of optical fiber used in cables that consist of a core and cladding with a refractive index that gradually decreases with distance from the fiber axis. This type of fiber is also known as index-graded fiber or gradient-index fiber. Graded-index fiber has a higher refractive index in its center than at its edges, allowing light to be propagated in a more uniform way and reducing the amount of light lost in the cable.
Graded-index fiber is commonly used in telecommunications cables due to its superior performance compared to conventional step-index fibers. With traditional step-index fibers, light is reflected at the core-cladding interface and therefore some of the light is lost. This is known as total internal reflection. With graded-index fibers, however, the refractive index changes gradually, so that the reflected light is spread over a greater area, resulting in less light lost in the cable.
Graded-index fibers also have better bandwidth, meaning that more data can be transmitted over a given length of cable. This makes them ideal for high-speed data communication applications such as voice, video, and data transmission. Additionally, graded-index fibers are more resistant to bending and can be used in a variety of configurations, making them an attractive choice for a variety of applications.
In summary, graded-index fiber is an optical fiber used in cables that consist of a core and cladding with a refractive index that gradually decreases with distance from the fiber axis. This type of fiber provides superior performance compared to traditional step-index fibers, including better bandwidth, lower light losses, and improved resistance to bending. As such, graded-index fiber is commonly used in telecommunications cables and is an ideal choice for high-speed data communication applications.