The methods mainly include permanent connection, emergency connection and active connection.

1. Permanent optical fiber connection (also called hot melt):

This connection is to melt the connection point of two optical fibers and connect them together by means of electric discharge. Generally used in long-distance connection, permanent or semi-permanent fixed connection. Its main feature is that the connection attenuation is the lowest among all connection methods, with a typical value of 0.01~0.03dB/point. However, when connecting, special equipment (fusion machine) and professionals are required to operate, and the connection point also needs to be protected by a special container.

2. Emergency connection (also called) cold melting:

The emergency connection mainly uses mechanical and chemical methods to fix and bond the two optical fibers together. The main feature of this method is that the connection is fast and reliable, and the typical attenuation of the connection is 0.1~0.3dB/point. However, the long-term use of the connection point will be unstable, and the attenuation will increase greatly, so it can only be used for emergency use in a short time.

3. Active connection:

Active connection is a method of connecting site to site or site to fiber optic cable using various fiber optic connection devices (plugs and sockets). This method is flexible, simple, convenient and reliable, and is mostly used in computer network wiring in buildings. Its typical attenuation is 1dB/connector.

What matters should be paid attention to in the construction of optical cable?

Outdoor construction of optical cable

The most important thing for long-distance fiber optic cable laying is to choose a suitable path. The shortest path is not necessarily the best, but also pay attention to the right to use the land, the possibility of erection or burial, etc.

There must be very complete design and construction drawings, so that the construction and future inspections are convenient and reliable. During construction, always be careful not to put the cable under heavy pressure or be injured by hard objects. When the cable turns, its turning radius should be greater than 20 times the diameter of the cable itself.

Construction of outdoor aerial optical cable:

A. The overhead method of hanging wire brackets is simple and cheap, and it is the most widely used in my country, but it is time-consuming to add hooks and arrange them.

B. Hanging wire winding overhead method, this method is more stable and less maintenance work. But a special wrapping machine is required.

C. The self-supporting overhead method has high requirements on the trunk line, difficult construction and maintenance, and high cost. It is rarely used in China at present.

D. When overhead, a guiding device must be added at the place where the optical cable leads to the trunk, and the optical cable should not be dragged to the ground. Pay attention to reducing friction when pulling the optical cable. A length of fiber optic cable should be left on each trunk for expansion and contraction.

E. Pay attention to the reliable grounding of metal objects in the optical cable. Especially in mountainous areas, high-voltage power grid areas and many areas, there are generally 3 grounding points per kilometer, and even non-metallic optical cables are used.

Outdoor pipeline optical cable construction:

A. Before construction, the occupancy of the pipeline should be checked, the plastic sub-pipes should be cleaned and placed, and the traction line should be placed at the same time.

B. Calculate the deployment length, and there must be enough reserved length.

C. The length of one laying should not be too long (generally 2KM). When wiring, it should be pulled from the middle to both sides.

D. The traction force of the cable is generally not more than 120kg, and the reinforcing core part of the optical cable should be pulled, and the waterproof and strengthening treatment of the head of the optical cable should be done.

E. The lead-in and lead-out of the optical cable must be equipped with a guide device, and the floor cannot be directly mopped.

F, pipeline optical cable should also pay attention to reliable grounding.