纤维波导的运转受到几何光学的简单规律和电磁理论支配。以恰当的角度射入纤维的光将在壁上经受内反射并将沿着纤维的长度传播,直至被吸收和散射机理所衰减。用较低折射率材料包复纤维的心蕊材料涂层以获得一个受保护的反射界面,并且通过使用均匀的、超高纯的玻璃,光学纤维已获得了小于1分贝/千米的衰减,这比一般的同轴光缆获得的值低得多。目前使用的纤维光缆的损耗一般在6～10分贝/千米的范围。一条基 The operation of the fiber waveguide is governed by the simple laws of geometrical optics and the electromagnetic theory. Light entering the fiber at an appropriate angle will undergo internal reflection on the wall and will propagate along the length of the fiber until it is attenuated by the absorption and scattering mechanisms. The core material of the fiber is coated with a lower refractive index material to obtain a protected reflective interface and by using uniform, ultra-high purity glass, the optical fiber has achieved an attenuation of less than 1 dB / km, This is much lower than the value obtained with a typical coaxial cable. The current loss of fiber optic cable is generally in the range of 6 to 10 dB / km. A base