Fiber Optic Loss Budget Calculator

An optical power budget are the measurement of a total amount of light loss between the optical transmitter and the optical receiver. The optical power budget is important in determining whether the optical signal are strong enough for the optical receiver to be able to detect the signal. If the optical power budget is too low, the optical signal will be too weakly for the optical receiver to function correctly; weak signals can result in data packet losses or a loss of connectivity altogether.

For these reason, it is necesary to calculate the optical power budget for a fiber-optic network to ensure that the signal remains strong enough to remain above the sensitivity of the optical receiver. Optical power loss can occur at various point within the fiber optic network. For start, optical power loss can occur as the signal travel through the kilometers of the fiber optic cable.

What is an Optical Power Budget?

Additionally, optical power loss can occur at every connector and splice locate within the network. Using single mode OS2 fiber can reduce the attenuation of the fiber optic cable; single-mode OS2 fiber have low attenuation and loses very little power along each kilometer of the fiber optic cable. Multimode OM4 fiber, on the other hand, has high attenuation; it loses a large amount of optical power along each kilometer of the fiber optic cable.

OM4 fiber is only design for short distances within the network. Lastly, the wavelength of the optical signal can also impact the attenuation of the fiber optic cable. In a PON network, splitters can cause significant loss of optical power.

Each splitter divide the optical signal to several subscribers. However, every splitter also reduce the amount of optical power that is delivered to each subscriber. The more splitters installed in the network, the more losses in optical power will occur.

Additionally, every connector within the network also contribute to the total optical power loss of the network. Each mated pair of connectors will contribute to the total optical power loss in the network in terms of decibels of optical power loss. Lastly, splices will also contribute to the total optical power loss of the network; however, there will be less loss compared than the connectors.

The more splices that people install within the network, the more the optical power loss will increase. It is important to include a margin of safety within the optical power budget calculations. A margin of safety allow for the optical power budget calculations to account for unknown loss of optical power that may occur within the network.

The connectors within the network can become dirty. Dirty connectors will lead to increased loss of optical power. Additionally, the environment in which the network is installed can change over time.

These changes can increase optical power loss. Without including a margin of safety for optical power loss, the optical power budget calculations may come to a negative optical power budget; a negative optical power budget indicate that the optical signal will not be strong enough to maintain a connection to the network. Finally, it is also important to examine the entire path of the optical signal from the splitter to the end user.

It is easy to forget to include the optical power loss that occur within the drop legs between the splitter and the end user. The drop legs contribute to the total optical power loss within the network. By taking into account each connector, each splitter, each splice, and each meter of the installed fiber optic cable, the optical power budget will be accurate.

By ensuring that the optical power budget is accurate, the signal will be strong enough to reach the optical receiver. Additionally, the network will remain reliable and functional.