2. Overview
1. The need for testing
2. Testing devices
3. Problems with today’s equipment.
4. Cost of equipment
3. Importance of Testing
Ensure the fiber has been Properly installed
Check IL and reflectance of all splices and connections
Providers must maintain high quality of customer service
Quickly locate problem areas for repair
4. Types of Testing
• End to End loss testing
• Cable Commissioning
• Splice and connector optimization
• System ORL characterization
• Dispersion verification and wavelength
measurements
5. End to End Testing
• Both units must be
referenced with the
test jumpers
• Confirm power source
is connected to test
fiber
• Reading is only
accurate if both units
at same wavelength
6. Cable Commissioning
• Tests the cable for damage
• Double checks length and attenuation
• And measures the polarization mode dispersion
7. Reflectance
• Do to glass air
interface
• Rayleigh
backscattering
• Pr = Reflected
Power
• Pi = Incident Power
8. Reflectometers
• Two types:
1. Optical Time Domain Reflectometer
- Measures reflectance and ORL
- Can characterize connectors and mechanical splices
- Accuracy of plus/minus 2dB
9. Reflectometer
2. Optical Continuous Wave Reflectometer
- Also measures reflectance and ORL
- Some units measure bi-directional loss
- Accuracy of plus/minus 0.4 dB to 1.0 dB
10. Difficulties
• Light source and power meter must be
referenced at the same point.
• Wavelength of light source and power
meter must be the same.
• Jumpers to test equipment can wear down
