A. Generally, the recommended ferrule hole size for 125µm singlemode fiber is 126µm. The 126µm hole allows for some epoxy bond around the fiber, and for ease of fiber insertion without breakage. However, there are some 125.5µm ferrules available for critical alignment situations.

Q. I am sending video on a singlemode fiber from building A to building B. Can I also send video from building B back to building A on the same singlemode fiber?

A. By using WDM's (Wave Division Multiplexers), you can send two different signals on the same fiber in opposite directions. A WDM is generally a 1x2 device similar to a coupler or splitter, except that it will separate and/or combine wavelengths on a single fiber. For example, if your current video system is transmitting at 1550nm, you could install a WDM at each end of the cable and use a 1310nm transmitter and receiver to send and receive video in the reverse direction.

Q. What happens if I were to feed an optical node with too much light?

A. If the received light level is too high for the detector in an active node, it can overdrive the detector and create noise in the signal. Worse, it can damage the unit. To prevent this problem, use an attenuator. These devices are available as either fixed or variable attenuators. Styles include pigtailed devices, bulkhead adapters, and male-to-female hybrids. To determine the amount of attenuation needed, simply measure the power of the signal being received, then subtract the maximum input power of the active equipment from the measured power of the signal.