The main methods are permanent connection, emergency connection and active connection.

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

The connection is made by melting and connecting the connection points of two optical fibers together by means of electric discharge. Generally used in long distance connections, permanent or semi-permanent fixed connections. Its main characteristic is that the connection attenuation is the lowest among all connection methods, with the typical value of 0.01~0.03dB/ point. But when the connection, need special equipment (welding machine) and professional personnel for operation, and the connection point also need special container protection.

2. Emergency connection (also known as cold fusion) :

Emergency connection is mainly mechanical and chemical method, two optical fiber fixed and glued together. The main characteristic of this method is that the connection is fast and reliable, and the typical attenuation of the connection is 0.1~ 0.3db/point. But the connection point long-term use will be unstable, attenuation will also increase significantly, so only a short period of time should be used urgently.

3. Active connection:

Active connection is a method of connecting a site to a site or site to a cable using various optical fiber connection devices (plugs and sockets). This method is flexible, simple, convenient and reliable. Its typical attenuation is 1dB/ connector.