The optical fiber fusion splicer is the most widely used splicing method in optical fiber engineering. Its principle is to use the arc fusion splicing method to generate a high temperature above 2000 ℃ by arc discharge to fuse two optical fibers into one optical fiber. A high-performance optical fiber fusion splicer must be configured for fiber fusion splicing projects. The structure of the optical fiber fusion splicer consists of the following parts.
1. Display screen of fusion splicer
The fusion splicer uses an infrared light source and a display screen to observe the entire fiber fusion splicing process, and the magnification of the fiber can reach 200-300 times. Many brand models used to change the focal length to observe the X and Y directions of the fiber separately, and the splicing speed was very slow. Current fusion splicers generally use the direct view of the fiber core (PAS) to monitor the alignment. The liquid crystal display can simultaneously display the fiber splicing process in the X and Y directions to observe the fiber status and splicing quality. The splicing speed is faster.
The controller usually includes two parts: a monitoring unit and a microprocessor. The monitoring unit is the monitoring of the local optical power. The microprocessor completes the automatic adjustment and connection loss estimation. The discharge time and discharge current can be adjusted by changing the computer program. The third-generation machine uses a high-resolution camera to view the fiber vertically and displays the fiber image on the phosphor screen, and uses the lens effect of the fiber cladding to directly display the alignment of the fiber core. At the same time, the camera provides this observation information to the central micro-processing controller, and the central controller controls the fine-tuning machine for automatic alignment, and controls the indirect estimation of discharge and fiber connection loss.
3. High pressure source of heating furnace
There are two main types of high-voltage sources. One high-voltage source boosts 50 Hz, 220V alternating current to 3000-4OOOV with a current of about 20 mA; the other is a high-frequency power supply of 20 Hz or 40 kHz. The high-frequency source of high-frequency mode has the characteristics of small size of transformer, high efficiency, and the use of integrated circuits in the circuit, so it is used most in actual engineering practice.
4. Discharge electrode
A pair of electrodes with 300 conical tips are processed from tungsten rods and installed on the electrode holder of the welding machine. The distance between the electrode tips is generally 0.7mm. When the optical fiber is connected, an arc is generated between the electrodes through the discharge of the electrodes, and the instantaneous temperature reaches about 2000 ℃, which melts the optical fiber at the center of the arc. After the electrode has been used for a period of time, there will be an oxidized adhesion layer on the surface, and the electrode should be removed regularly. Generally, ordinary electrodes are discharged for 2000 times. If the electrodes are used after excessive consumption, the quality of the optical fiber connection will be affected.
5. Core adjustment frame
The core adjustment device of the optical fiber fusion splicer is also called the debugging frame, which is usually a “lever” type fine adjustment mechanism. The three-dimensional fine-tuning of the V-shaped groove is achieved by a spiral micrometer mounted on the end of the long rod. The optical fiber placed in the V-shaped groove is fixed by a mechanical pressing plate. X, Y direction fine adjustment is driven by the servo motor, the lever mechanism is to make the adjustment more precise, and the axial (Z direction) adjustment is moved by the screw micrometer. This mechanism has a fine tuning range of 105m dB, the adjustment accuracy is ±0.1μm, and the Z-axis displacement accuracy is better than 1μm.
Post time: 2021-02-25