What Is The Principle And Function Of Fiber Optic Cable

Optical fiber transmission is based on the principle of total reflection of available light at the interface of two media. Step-index fiber, n1 is the refractive index of fiber core medium, n2 for the refractive index of cladding medium, n1 is greater than the n2, the arrival of light entering the fiber core fiber core and cladding interface (hereinafter referred to as core - package interface) when the incident Angle is greater than the total reflection of critical Angle theta, c is total reflection can happen without light energy high fiber core, the incident light can forward by countless times total reflection at the interface between the transmission. It turns out that when the optical fiber is bent, the interface normal turns and the incident Angle is small, so some of the incident Angle of light becomes less than theta and cannot be fully reflected. But the light from the larger incident Angle can still be completely reflected, so the fiber can still transmit when it bends, but it will cause energy loss. In general, when the bending radius is greater than 50 ~ 100 mm, the loss is negligible. Small bending will cause serious "micro bending loss".