How can you troubleshoot a fiber optic cable with high attenuation?

1 Identify the source

The first step in troubleshooting a fiber optic cable with high attenuation is to identify the source of the problem. You can use a light source and a power meter to measure the input and output power of the cable and calculate the attenuation. Alternatively, you can use an optical time domain reflectometer (OTDR), which is a device that sends a pulse of light through the cable and measures the reflections along the way. The OTDR can show you the location and magnitude of any anomalies or faults in the cable that cause attenuation.

2 Check the connectors

The second step in troubleshooting a fiber optic cable with high attenuation is to check the connectors. Connectors are the devices that join two fiber ends together or connect a fiber to a device. Connectors can introduce attenuation due to misalignment, dirt, damage, or poor quality. You can inspect the connectors visually with a microscope or a fiber scope and clean them with a lint-free cloth or a special cleaning kit. You can also test the connectors with a light source and a power meter or an OTDR and replace them if they are faulty.

3 Check the splices

The third step in troubleshooting a fiber optic cable with high attenuation is to check the splices. Splices are the permanent or temporary joints that connect two fiber segments together. Splices can introduce attenuation due to poor alignment, air gaps, bubbles, or defects. You can inspect the splices visually with a microscope or a fiber scope and repair them with a fusion splicer or a mechanical splice kit. You can also test the splices with a light source and a power meter or an OTDR and replace them if they are defective.

4 Check the bends

The fourth step in troubleshooting a fiber optic cable with high attenuation is to check the bends. Bends are the curves or twists that occur in the fiber due to installation, handling, or routing. Bends can introduce attenuation due to macrobending or microbending. Macro-bending occurs when the fiber radius is larger than the minimum bend radius specified by the manufacturer and causes light to leak out of the fiber core. Micro-bending occurs when the fiber is compressed or stretched by external forces and causes light to scatter within the fiber core. You can inspect the bends visually and straighten them or relocate them if they are excessive. You can also test the bends with a light source and a power meter or an OTDR and replace the cable if it is damaged.

5 Check the environment

The fifth step in troubleshooting a fiber optic cable with high attenuation is to check the environment. The environment can affect the attenuation of the fiber due to temperature, humidity, vibration, or chemical exposure. Temperature can cause expansion or contraction of the fiber and alter its refractive index. Humidity can cause water absorption or condensation in the fiber and increase its attenuation. Vibration can cause micro-bending or stress in the fiber and reduce its strength. Chemical exposure can cause corrosion or degradation of the fiber and impair its transmission. You can inspect the environment and monitor its conditions and adjust them if they are outside the recommended range. You can also test the environment with a light source and a power meter or an OTDR and replace the cable if it is deteriorated.

6 Check the system

The sixth step in troubleshooting a fiber optic cable with high attenuation is to check the system. The system is the combination of the transmitter, the receiver, and the cable that form the communication link. The system can introduce attenuation due to mismatched wavelengths, incompatible modalities, or insufficient power budget. Wavelength mismatch occurs when the transmitter and the receiver operate at different frequencies and cause signal loss. Modality mismatch occurs when the transmitter and the receiver use different modes of light propagation and cause signal distortion. Power budget is the difference between the transmitter output power and the receiver sensitivity and determines the maximum attenuation that the system can tolerate. You can inspect the system and verify its specifications and compatibility and adjust them if they are incorrect. You can also test the system with a light source and a power meter or an OTDR and replace the components if they are malfunctioning.

7 Here’s what else to consider

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