The difference between optical fiber cold splicing and optical fiber fusion splicing

Updated on Mon Aug 18 2025

Optical fiber transmission has the advantages of wide transmission frequency, large communication capacity, low loss, no electromagnetic interference, small diameter of optical cable, light weight, rich source of raw materials, etc., so it is becoming a new transmission medium. When light is transmitted in an optical fiber, a loss will occur, and this loss is mainly composed of the transmission loss of the optical fiber itself and the splice loss at the optical fiber joint.


Once the optical cable is ordered, the transmission loss of the optical fiber itself is basically determined, and the splice loss at the optical fiber joint is related to the optical fiber itself and on-site construction. Efforts to reduce the splice loss at the optical fiber joint can increase the optical fiber relay amplification transmission distance and improve the attenuation margin of the optical fiber link.


Cold splicing of optical fibers

It is used for optical fiber butt optical fiber or optical fiber docking pigtail, which is equivalent to making a joint, (fiber docking pigtail refers to the butt joint between the optical fiber and the core of the pigtail, not the pigtail head mentioned by the former), which is used for this kind of cold splicing. Something called a fiber optic cold splicer. The optical fiber cold splicer is used when the two pigtails are butted. The main component inside is a precise v-groove. After the two pigtails are pulled out, the cold splicer is used to realize the butt of the two pigtails. It is easier and faster to operate and saves time than welding with a welding machine. There are generally two forms of cold splicing: the first field quick connector that ends up; the second type of cold splicing for optical fiber butt joints.


With the rapid development of FTTH fiber-to-the-home, the demand for optical fiber cold splices has also greatly increased.

FTTH cable

Optical fiber quick connectors and optical fiber cold splices will play an irreplaceable role in FTTH access. The field termination technology of optical fiber quick connectors just solves this problem. The operation is convenient and fast without fusion splicing, and the connection cost is low, which truly realizes access anytime, anywhere. .


It is used for optical fiber butt optical fiber or optical fiber docking pigtail, which is equivalent to making a joint, (fiber docking pigtail refers to the butt joint between the optical fiber and the core of the pigtail, not the pigtail head mentioned by the former), which is used for this kind of cold splicing. Something called a fiber optic cold splicer. The optical fiber cold splicer is used when the two pigtails are butted. The main component inside is a precise v-groove. After the two pigtails are pulled out, the cold splicer is used to realize the butt of the two pigtails. It is easier and faster to operate and saves time than welding with a welding machine.


Fiber optic cable fusion

Fiber optic cable fusion is a meticulous work, especially in the process of end face preparation, fusion splicing, fiber coiling, etc., which requires the operator to observe carefully, consider carefully, and operate in a standardized way.


When light is transmitted in an optical fiber, a loss will occur, and this loss is mainly composed of the transmission loss of the optical fiber itself and the splice loss at the optical fiber joint. Once the optical cable is ordered, the transmission loss of the optical fiber itself is basically determined, and the splice loss at the optical fiber joint is related to the optical fiber itself and on-site construction. Efforts to reduce the splice loss at the optical fiber joint can increase the optical fiber relay amplification transmission distance and improve the attenuation margin of the optical fiber link.


The difference between optical fiber cold splicing and optical fiber fusion splicing

The difference between cold splicing and welding

Hot Melt

A fusion splicer and a fiber cutter are required to connect the two fibers, and no other auxiliary materials are required. The advantage is that the quality is stable and the connection loss is small (about 0.03 to 0.05db), but the disadvantage is that the equipment cost is too high, the power storage capacity of the equipment is limited, and the field operation is limited. In short, the welding quality is good and the attenuation is low, but the operation is troublesome and a welding machine is required.


cold connection

It does not need too much equipment, just a fiber cutter, but each contact needs a quick connector (it can be said to be the mainstream operation in the future). The advantage is that it is easy to operate and suitable for field operations. Each point. Cold splices", at present, there are few domestic manufacturers that can directly produce, the cost is high, there is no room for choice in business and technical services, followed by the use of matching liquid in the cold splices, due to less use, Time is short, and aging issues take the test of time.


In summary:

1. The cost of cold connection is much higher than that of hot melt, and the price of hot melt tube is very low.

2. The tools for cold splicing are more convenient to carry, while for hot splicing, you need to carry the smelting machine on your back. Very inconvenient.

3. The optical fiber loss after hot-melting is low, and the optical fiber connector of cold splicing is relatively large in loss.


Introduction to Optical Fiber Splicing Technology

What is a fiber cleaver?

Answer: Optical fiber cutting machine, that is, a device that cuts optical fibers and other cables in a fixed way. The main function is to achieve standard smoothness and smooth incision, and prepare for the next step of optical fiber welding.


What is a fiber fusion splicer?

Answer: The optical fiber fusion splicer is to fuse and connect the cut optical fibers at both ends according to the standard parameters, so that the light can transmit signals normally on the line.


What is it mainly used for?

Answer: These two devices are usually placed as a whole toolbox, mainly used in the place where optical fibers are used to transmit signals in engineering, because the connection and access of optical fibers must involve the seamless connection of optical fibers


Mainly who needs it?

A: Now there is a special training section to train optical fiber welding personnel. This is mainly for training, and has nothing to do with education. It is mainly used for information engineering personnel.


Main Factors Affecting Fiber Splice Loss

There are many factors that affect the loss of optical fiber fusion, which can be roughly divided into two categories: intrinsic factors and extrinsic factors of optical fibers.

1. The intrinsic factor of the fiber refers to the factor of the fiber itself, and there are four main points.

(1) The fiber mode field diameter is inconsistent;

(2) The core diameters of the two optical fibers are mismatched;

(3) The core section is not round;

(4) The concentricity between the core and the cladding is not good.


2. The extrinsic factor that affects the optical fiber splice loss is the splice technology.

3. The influence of other factors. The operation level of the splicer, the operation steps, the fiber coil process level, the cleanliness of the electrodes in the fusion splicer, the splicing parameter settings, and the cleanliness of the working environment will all affect the value of the splicing loss.



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