Fiber core cracking refers to the occurrence of cracks or fractures in the core of an optical fiber, which can cause severe attenuation or even complete interruption of optical signals during transmission. Solving the problem of fiber optic core cracking requires a series of diagnostic, repair, and preventive measures, which will be analyzed in detail in this article.
一, Diagnosis and localization
1. Optical Time Domain Reflectometer (OTDR)
Tool: OTDR (Optical Time Domain Reflectometer) is a commonly used tool for detecting fiber optic faults.
Method: By sending optical pulses and measuring the reflected light returned, OTDR can determine the location of breakpoints, joints, bends, and other points in the optical fiber.
Result: OTDR can provide the length, attenuation curve, and location of the fault point of the optical fiber, helping technicians accurately locate the location of the crack core.
二, Fault point repair
1. Fiber optic fusion splicing
Applicable situation: If the location of the crack core is clear and the crack core is short, fiber fusion splicing technology can be used for repair.
Steps:
Preparation: Use a fiber optic cutting knife to cut off the damaged part, ensuring that the fiber end faces at both ends are flat.
Cleaning: Clean the fiber optic end face with an alcohol swab to ensure there is no dust or stains.
Alignment: Place two sections of optical fiber into the fusion splicer, ensuring that the fiber cores are aligned.
Fusion splicing: Start the fusion splicing machine, which will automatically complete the fusion splicing process of the optical fiber.
Testing: Use OTDR or optical power meter to test the fused optical fiber to ensure normal signal transmission.
Attention: Ensure the cleanliness and calibration of the welding machine before welding, and carefully check the quality of the welding point after welding.
2. Fiber optic cold junction
Applicable situation: If the on-site welding conditions are not available, fiber optic cold splicing technology can be used.
Steps:
Preparation: Use a fiber optic cutting knife to cut off the damaged part, ensuring that the fiber end faces at both ends are flat.
Cleaning: Clean the fiber end face with an alcohol swab.
Installation: Insert the optical fiber into the cold connector, ensuring that the fiber core is aligned.
Fixed: Use a specialized tool to fix the cold connector onto the optical fiber.
Testing: Use OTDR or optical power meter to test the cold connected optical fiber to ensure normal signal transmission.
Attention: The quality and installation techniques of cold connectors have a significant impact on the repair effect. Ensure the use of high-quality cold connectors and correct installation methods.
三, Replace fiber optic cables
1. Partial replacement
Applicable situation: If the crack core position is too long or multiple fusion splicing cannot solve the problem, local replacement of the optical fiber can be considered.
Steps:
Positioning: Determine the starting and ending positions of the crack core.
Cutting: Leave a healthy section of optical fiber at each end of the split core, and use a fiber cutting knife to cut off the split core.
Prepare a new fiber optic cable: Prepare a new fiber optic cable of the same specifications.
Fusion splicing: Weld the two ends of the new fiber and the original fiber separately.
Testing: Use OTDR or optical power meter to test the fused optical fiber to ensure normal signal transmission.
Attention: Ensure that the specifications of the new fiber are consistent with those of the original fiber, and that the quality of the fusion point is high.
2. Whole replacement
Applicable situation: If there are multiple cracked core locations or multiple damaged parts of the entire optical fiber, it may be considered to replace the entire fiber.
Steps:
Preparation: Prepare a new optical fiber of the same specifications.
Dismantling old optical fibers: Carefully dismantle old optical fibers, being careful not to damage other equipment and circuits.
Install new optical fiber: Lay the new optical fiber according to the original path, ensuring that the wiring is reasonable and firmly fixed.
Welding: Welding is carried out where necessary.
Testing: Use OTDR or optical power meter to test the new optical fiber to ensure normal signal transmission.
Attention: When laying new optical fibers, avoid excessive stretching or bending, and ensure that the routing path of the new fibers is consistent with the original path.
四, Preventive measures
1. Standardized operation
Training: Regularly train technical personnel to ensure they are familiar with the installation, maintenance, and repair operations of optical fibers.
Tools: Use high-quality fiber optic cutting knives, fusion splicers, and other tools to ensure operational accuracy.
2. Environmental Protection
Temperature: Avoid prolonged exposure of optical fibers to extreme temperature environments, especially under high or low temperature conditions.
Humidity: Keep the environment for storing and using optical fibers dry and avoid moisture.
3. Physical protection
Fixed: Ensure that the optical fiber is firmly fixed during the wiring process, avoiding excessive stretching or bending.
Protection: Use fiber optic protective sleeves or pipelines to prevent external physical damage.
Identification: Mark at key locations to avoid accidental damage to optical fibers during construction or other operations.
五, Monitoring and maintenance
Regular inspection: Regularly use OTDR and other tools to inspect optical fibers and promptly identify potential issues.
Record: Record the results of each inspection and maintenance, establish a fiber optic maintenance file for easy tracking and management.
Backup: For important lines, redundant paths can be considered to improve system reliability.
六, Special case handling
1. Long distance fiber optic split core
Applicable situation: For long-distance transmission optical fibers, if the crack core is located far away, on-site repair is difficult.
Steps:
Remote diagnosis: Use a remote monitoring system for preliminary diagnosis and determine the location of the crack core.
Dispatch maintenance team: Dispatch a professional maintenance team to the site for repair.
Temporary replacement: During the repair period, backup lines or wireless transmission can be considered to ensure uninterrupted communication.
2. Core cracking in complex environments
Applicable situation: In complex environments such as underground, underwater, and high-altitude, repairing fiber optic core cracks is more difficult.
Steps:
Professional equipment: Use professional detection and repair equipment, such as underwater robots, aerial work vehicles, etc.
Special tools: Use special tools suitable for complex environments, such as waterproof welding machines, dustproof cold connectors, etc.
Emergency plan: Develop detailed emergency plans to ensure quick response in case of emergencies.
