Introduction and advantages and disadvantages of optical fiber transmission technology

The transmission mode of optical fiber transmission equipment can be simply divided into: multi-mode optical fiber transmission equipment and single-mode optical fiber transmission equipment. Optical fiber can be used not only to transmit analog and digital signals, but also to meet the needs of video transmission. Its data transmission rate can reach several thousand Mbps. If the repeater is not used, the transmission range can reach 6-8km.

Optical fiber transmission materials

The optical fiber used in the integrated wiring system is a glass multi-mode LED with a wavelength of 850nm, with a transmission rate of 100Mbps and an effective range of about 20Km. Its core and cladding are composed of two media with different optical properties. The refractive index of the inner medium to light is higher than the refractive index of the surrounding medium. It can be known from physics that at the interface of two media, when light enters the side with low refractive index from the side with high refractive index, as long as the incident angle is greater than a critical value, reflection will occur and the energy will not be affected to loss. At this time, the covering layer wrapped around the periphery is like an opaque substance, preventing light from escaping from the surface during the penetration process.

The produced optical fiber, whether it is a glass medium or a plastic medium, can transmit all visible light and part of the infrared spectrum. Optical cables made of optical fibers have a variety of structural forms.

There are two main types of optical cables for short distances:

A layered optical cable has steel wire or nylon wire in the center, several optical fibers in the outer bundle, and a plastic sheath on the outside;

The other is a high-density optical cable, which is made up of multiple layers of ribbons, each layer of ribbon laid parallel to a row of optical fibers.

Optical fiber transmission process

Optical fiber transmission is a light-emitting diode LED or injection laser diode ILD that sends out a light signal that travels along the optical medium. At the other end, a PIN or APD photodiode is used as a detector to receive the signal. The modulation of the optical carrier is the amplitude shift keying method, also known as the intensity modulation (Intensity Modulation). The typical approach is to represent two binary numbers with the appearance and disappearance of light at a given frequency. The signal of the light emitting diode LED and the injection laser diode ILD can be modulated in this way, and the PIN and ILD detectors directly respond to the brightness modulation.

Power amplification: Place the optical amplifier before the optical transmitter to increase the optical power of the fiber. The optical power of the entire line system is improved. Online relay amplification: When the building group is large or the distance between the buildings is far, it can play the role of relay amplification and increase the optical power. Pre-amplification: Amplify the micro signal after the photodetector at the receiving end to improve the receiving ability.

Advantages and disadvantages of optical fiber transmission


1. High sensitivity, free from electromagnetic noise interference.

2. Small size, light weight, long life and low price.

3. Insulation, high pressure resistance, high temperature resistance, corrosion resistance, suitable for work in special environments.

4. The geometric shape can be adjusted according to environmental requirements, and the signal transmission is easy.

5. High bandwidth, large communication volume, small attenuation, and long transmission distance.

6. The signal crosstalk is small and the transmission quality is high.

7. High confidentiality.

8. Easy to lay and transport materials.


1. The texture is brittle and the mechanical strength is poor.

2. The cutting and connecting of optical fiber requires certain tools, equipment and technology.

Post time: 2021-02-18


Lomoveishiy – Finland

I needed those to connect my PC on the third floor to have internet access in that room, and ISP installed their modem on the first floor only. After dropping fiber patch cables, plugged in all cables into these media converters at both sides, and link came up instantly. Was much easier than I thought!

Raymond – USA

Great experience – units worked straight out of the box – just needed plug in cables and we were done. I also like the possibility to enable jumbo frames, while we do not have a need for this feature at the current moment it’s great to have this option.

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