(1) Light transmitter
Light transmitter is to achieve electrical / optical conversion of Optical. It consists of a light source, driver and modulator. Its function is to electrical signals from the electrical end machine for light emitted from the light source is modulated, become modulated light, and then the modulated optical signal is coupled into an optical fiber or optical cable to transmit. Electric end machine is conventional electronic communication devices.

(2) Light receiver
Light receiver is to achieve optical / electrical conversion of Optical. It consists of a light detector and optical amplifier. Its function is to fiber or cable optical signal transmitted through the optical detector into electrical signals, then this weak signal by the amplifier circuit to a sufficient level, to the electrical terminal receiving end of the drain to go.

(3) fiber or cable
Optical fibers or optical cable constituting the optical transmission path. Its function is modulated optical signals emitted by the transmitter end, after a long-distance transmission optical fiber or optical cable coupled to the receiving end of the optical detector up, completion of the transfer of information tasks.

(4) Repeater
Repeaters by the light detector, a light source and decision regeneration circuit. Its role is twofold: one is to compensate an optical signal transmitted by the fiber attenuation; the other is a pulse waveform distortion near the line shaping.

(5) fiber optic connectors, couplers and other passive components
Since the length of the optical fiber or cable is limited fiber drawing process and fiber optic cable construction conditions and the length of the fiber drawing is limited (eg 1Km). Therefore, there may be problems plurality of optical fibers connected to an optical fiber line. Thus, the link between the fibers; and Optical fiber coupling, the use of fiber optic connectors, couplers and other passive components is essential.