Basic Components of Optical Fiber Communication System

1.Send part:
The pulse modulation signal output by the electrical transmitter (electric terminal) is sent to the optical transmitter. The main function of the optical transmitter is to convert the electrical signal into an optical signal and couple it into the optical fiber.

2. Receive part: 

Convert the optical signal transmitted through the optical fiber into an electrical signal, process the electrical signal to restore it to the original pulse modulation signal and send it to the electrical end machines (process the electrical signal sent by the optical receiver, waveform shaping, coding Type inverse transformation...get a suitable electrical signal and send it back to the program-controlled switch)

3. Transmission part:
Single-mode fiber, optical repeater.
(1) Optical transmitter: It is an optical transceiver that realizes electrical/optical conversion. It is composed of a light source, a driver and a modulator. Its function is to modulate the light wave emitted by the light source with the electrical signal from the electrical terminal to become a modulated light wave, and then couple the modulated light signal to the optical fiber or optical cable for transmission.
(2) Optical receiver: It is an optical transceiver that realizes optical/electrical conversion. It consists of an optical detection circuit and an optical amplifier. Its function is to convert the optical signal transmitted by the optical fiber or optical cable into an electrical signal through the optical detector. Then, the weak electrical signal is amplified to a sufficient level and sent to the receiving end of the electrical machine.
(3) Optical fiber/optical cable: Optical fiber or optical fiber cable constitutes the transmission path of light. The function is to couple the modulated light signal sent by the transmitting end to the optical detector at the receiving end after long-distance transmission by optical fiber or optical cable to complete the task of transmitting information.
(4) Optical repeater: It is composed of a photodetector, a light source and a judgment regeneration circuit. It has two functions: one is to compensate the attenuation of the optical signal when it is transmitted in the optical fiber; the other is to shape the waveform distorted pulse

(5) Passive devices such as optical fiber connectors and couplers (there is no need to supply power to them separately, but the devices still have losses): Because the length of optical fibers or optical cables is limited by the optical fiber drawing process and cable construction conditions, and the length is also limited (eg 2km). Therefore, a fiber line may have the problem of connecting multiple fibers. Therefore, the connection between optical fibers, the connection and coupling between optical fibers and optical terminals, and the use of passive components such as optical fiber connectors and couplers are essential.