An OTDR can be available with different fiber types or wavelengths, so that common applications can be matched. Testing at longer wavelengths like 1550 mm or 1625 mm can be utilized to find attenuation issues rather than splice and connector issues. The optical dynamic range of OTDR tools are limited by the optical pulse width, input sensitivity as well as signal integration time and output powers. The optical pulse signal and integration time can be adjusted on these tools. Longer laser pulses improve the range and attenuation measurement resolutions, but take away from the distance resolutions. Short pulse lengths will help the distance resolution of optical events and can reduce the range of measurement or attenuation measurement.
The most commonly used OTDR tools available on OTDR manufacturer offer leading technology with power meter functions in one unit. These tools are optimized for PON point to point testing inside of FTTx architectures due to the fact that many different wavelength configurations and options are available.
Many of these tools are designed for PON troubleshooting with an optional port for testing at a regular 1625 mm incorporating a filter that gets rid of unwanted 1310, 1490 and 1550 mm signals that can affect the measurement. The in service tool troubleshooting features of optical fiber is not interfering with normal operations, and are not seen to interfere with CO’s laser transmitters. These use out of band wavelengths as is stated for recommendation in the ITU-T L.41, which is the Maintenance Wavelength on Fibers Carrying Signals.