Optical fiber is used for many applications in almost every industry. The most common application is within cabled structures that are used for transmission of light or data. Many of us know that fibers are used for the internet communication network but optical fibers are also used in industrial welding applications to cut steel for building cars, medical applications where fibers are used for light transmission in endoscopes and removal of artery plaque, kidney stone, etc.
Due to the continuous development of light source and detection methods we see more and more new applications where detection of materials, gasses, temperatures, pressures, stress, vibration etc. is achieved by optics. Optical fibers are usually the extension media between light source and detector.
What makes optical fiber that special is often asked. We know that an optical fiber is composed of a very thin glass rod. The glass rod contains two parts, the core and the surrounding layer (cladding). By melting the glass rod in a draw tower, the optical fiber is extruded. By using different techniques in the manufacturing process of the glass rod, manufacturers are able to extrude fibers with different characteristics for their specific application.
How does it work? In most applications light is injected into the core of the glass fiber and follows the physical patch of the fiber due to the internal reflection between the core/cladding edge which acts as a mirror. When the fiber core is smaller in diameter, less of core/cladding reflection will occur allowing the light to transport more in a single mode (often compared with a tunnel vision). This allows faster transmission rates. With larger core fiber there is more reflections and dispersion however it offers other advantage transmission density and less of mechanical alignment precision on light source and detector.
