What is optical fiber?

Optical fiber consists of a core that confines a light and a cladding that reflects it. Confined in the core, the light travels through it as it is reflected by the cladding.

Optical fiber composed of a plastic core and a plastic cladding is called plastic optical fiber (APF or POF). Optical fiber composed of a quartz glass core and a plastic cladding is called plastic clad quartz optical fiber (PCF), and the one composed of a quartz glass core and a quartz cladding is called quartz optical fiber.