How To Weld Optical Fibers

Fiber optic welding refers to the use of fiber optic fusion splicers.
Testing requires the use of an optical time-domain reflectometer (OTDR). If it is used for light, a light source and an optical power meter can be used. A simple red light pen can also achieve this, but it cannot accurately measure light attenuation.
Welding steps for single core fiber fusion splicer:
1. Peel off the optical cable and secure it to the cable tray. Common optical cables include layer twisted, skeleton type, and central bundle tube type. Different types of optical cables require different stripping methods, and after stripping, the optical cable must be fixed to the reel frame.
2. Thread the stripped optical fibers through the heat shrink tubing separately. Different fiber bundles and colors should be separated and passed through heat shrink tubes separately.
3. Turn on the power of the welding machine and select the appropriate welding method. Common types and specifications of optical fibers include: SM dispersion non shifted single-mode fiber (ITU-T G.652), MM multimode fiber (ITU-T G.651), DS dispersion shifted single-mode fiber (ITU-T G.653), NZ non-zero dispersion shifted fiber (ITU-T G.655), BI bending resistant fiber (ITU-T G.657), etc. The appropriate fusion method should be selected according to different types of fibers, and the latest fiber fusion machines have the function of automatically identifying fibers, which can automatically identify various types of fibers.
4. Prepare fiber optic end faces. The quality of fiber optic end face production will directly affect the fusion quality, so qualified end faces must be prepared before fusion. Use a specialized wire stripping tool to peel off the coating layer, then wipe the bare fiber several times with a clean linen or cotton dipped in alcohol. Use a precision fiber cutting knife to cut the fiber. For 0.25mm (outer coated) fiber, the cutting length is 8mm to 16mm, and for 0.9mm (outer coated) fiber, the cutting length can only be 16mm.
5. Place the fiber optic cable. Place the fiber optic cable in the V-shaped groove of the fusion splicer, carefully press on the fiber optic pressure plate and fiber optic clamp, set the position of the fiber optic cable in the pressure plate according to the cutting length of the fiber optic cable, and correctly place it in the wind shield.
6. Connect the optical fiber. After pressing the continue button, the optical fiber moves in opposite directions. During the movement, a short discharge is generated to clean the surface of the optical fiber. When the gap between the fiber end faces is appropriate, the fusion splicer stops moving in opposite directions, sets the initial gap, measures the fusion splicer, and displays the cutting angle. After the initial gap setting is completed, the alignment of the fiber core or cladding begins, and then the fusion splicer reduces the gap (final gap setting). The arc generated by high-voltage discharge melts the left fiber into the right fiber. Finally, the microprocessor calculates the loss and displays the value on the display. If the estimated loss value is higher than expected, you can press the discharge button to discharge again, and the welding machine will still calculate the loss after discharge.
7. Remove the fiber optic and reinforce the fiber optic fusion joint with a heater. Open the windproof cover, take out the optical fiber from the fusion splicer, and then move the heat shrink tubing to the position of the fusion point, place it in the heater for heating, and after heating is completed, take out the optical fiber from the heater. When operating, do not touch the ceramic parts of the heat shrink tubing and heater due to the high temperature.
8. Disc the fiber and fix it. Connect the connected fiber optic cable tray to the fiber optic cable tray, fix the fiber optic cable, tray, junction box, terminal box, etc., and complete the operation.