Guided ray (acceptance angle)


A guided ray (also bound ray or trapped ray) is a ray of light in a multi-mode optical fiber ( type of optical fiber mostly used for communication over short distances), which is confined by the core. For step index fiber, light entering the fiber will be guided if it falls within the acceptance cone of the fiber, that is if it makes an angle with the fiber axis that is less than the acceptance angle.Rays that fall within this angular range are reflected from the core-cladding boundary by total internal reflection, and so are confined by the core.

Related formulas


θThe angle the ray makes with the fiber axis, before entering the fiber (degrees)
n0The refractive index along the central axis of the fiber (dimensionless)
ncThe refractive index of the cladding (dimensionless)