Fiber-Optic Communications James N. Downing

Chapter 10 Fiber-Optic Test and Measurement

10.1 Optical Power Management Types of Power Management –Measuring Component Power Levels Measure under steady state conditions Cutback method primarily (must cut the fiber) Can be made at the manufacturing location Can be performed in the field Attenuation –OTDR –Substitution method

10.1 Optical Power Management Power Measurement Instrumentation –Power meter measures power. –Loss set measures attenuation or losses. –Talk set sends signals to measure attenuation. –Optical time domain reflectometer measures power loss, fault location, and other power-related parameters.

10.2 Optical Wavelength Measurements Types of Wavelength Measurements –Peak wavelength –Linewidth information –Channel spacing –Linearity of channel amplitudes –Expansion availability –Security –Performance

10.2 Optical Wavelength Measurements Optical Spectra Instrumentation –Optical Spectrum Analyzer Measures wavelength and linewidth –Wavelength Meter Accurate wavelength measurements

10.3 Signal Measurements Dispersion and Data Rate Measurements –Must first change light into electrical signal –Oscilloscope Amplitude as a function of time Rise time Fall time Data rates

10.3 Signal Measurements Noise and Error Measurements –Eye-pattern analysis Measure multiple system noise and error parameters by using an oscilloscope –Spectrum analyzer Measures noise and BER levels Performs a Fourier transform to measure amplitude as a function of frequency –BER meter Digitized eye-pattern system

10.3 Signal Measurements Additional System Test and Measurement –Phase differences –Polarization