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1. What is Optical Power Meter
Many engineer confused why do I measure my PON system differently than a conventional fiber
with one wavelength? In a typical PON system there are two wavelengths on the incoming fiber.
This means that both data/video have been combined via a coupler to transmit on a single fiber. So
it is probable that you would have 1490nm and 1550nm on the same fiber.
In a conventional fiber optic system you would have only one wavelength on the fiber. In those
situations a optical power meter is fine because it will provide specific power level readings at
individual wavelengths. However in a PON system you have two wavelengths traveling on the
same fiber. So….in order to accurately measure performance at a specific wavelength you must
filter out the individual wavelengths I.E. 1490nm or 1550nm so that you can measure those
wavelengths independently. This type of “filtering” allows you to determine specific performance
of individual network elements.
In addition a complete PON Power Meter will allow you measure the specific power levels of
the incoming wavelengths and then pass the signal through to the ONT. This will than allow the
ONT to transmit a third wavelength back upstream and the PON meter can measure that
performance as well. This type of testing allows a complete performance evaluation of all the
network elements involved in a PON system. This type of performance is invaluable when
attempting to troubleshoot network performance. This cannot be accomplished with a standard
power meter.