Troubleshooting Your Fiber Optic System
Troubleshooting a fiber optic system may result in identifying too much or too little light. In the Cable TV or high data rate Telco applications, the problem may not be related to the intensity of light, but to the amount of light being reflected back which is called back reflection or Optical Return Loss (ORL). Looking through a window and seeing your reflection demonstrates back reflection. High back reflection is detrimental to signal quality.
To analyze high back reflection connections, an Optical Return Loss (ORL) unit or OTDR is used. The preparation of low back reflection connectors requires the exact measurement verification through an interferometer test.
The Interferometer test determines the quality of the ferrule surface using three measurements.
- The angle of the cut or radius on the end of a connector which determines actual back reflection values or characteristics.
- The undercut or protrusion of the fiber. This is measured against the ferrule end face determining how well the physical contact will be.
- The position of the fiber in relation to cut or curve, called the apex.
The installer is not expected to support the interferometer capability, but the cords may be sourced from a facility that does have the technology to provide low back reflection assemblies. In the meanwhile, installers concerned with high back reflection may use an ORL unit to troubleshoot their cords. It is not only the amount of light, but the reflected portions that determine network performance.
Back to Tips Listing
|
