The signal quality at an optical link output, not only depends on the quality of the input signals, but also on the optical link balance.
The optical balance can be defined as the right balance between the losses of the optical network, the optical power that the transmitter is able to provide, and the optical power necessary for the proper functioning of the receiver. These factors should be checked out to ensure the quality of the installation over time.
Measurement of optical losses
• The Televes multimetter H45 can calibrate and make attenuation measurements, automatically, at three wavelengths (1310, 11490 and 1550 nm) in combination with the triple light signal generator of Televes OPS 3L.
• You can also check the optical link losses by measuring the optical power at the transmitter output, and then repeat the process at the other end of the link. The difference between both powers measured will be the losses of the optical link.
Measurements of signal quality
After validating the optical network, we have to verify, in terms of quality, the impact that the optical transmitter/receiver may have on the original signal. Optical Fibre Measurements
Indeed, optical transmitters and receivers are active devices that will do a double transformation of the signal: the transmitter converts the electrical signal into an optical signal and the receiver does the reverse.
As with any electrical phenomenon, these transformations involve a slight qualitative degradation of the original signal. This slight degradation can be more or less aggravated depending on the transmitter or receiver input signals may be too strong or too weak, adding like this symptoms of
saturation, intermodulation and even noise.
Through its optical interface, the Televes H45 meter allows to make the signal quality measurements over coaxial cable as much as over optical fibre. All measures of the electrical signal quality at the transmitter input (BER, MER, C/N,..., etc.) can be carried out on the optical fibre at the output of the transmitter, whether they are digital (DVB-S, DVB-S2, DVB-T, DVB-T2 and DVB-C) or analog.
This way we can verify:
• The optimization of transmitted signals (qualitative comparison at the optical transmitter input and output).
• The proper functioning of the optical receiver (qualitative comparison to the input and output of the optical receiver).
The H45 meter with optical interface is a true multi-function tool that allows you to check easily, all the key points of a optical fibre installation