Fiber Optic Coupler Loss

Guidelines on what loss to expect when testing fiber optic cables to be able to judge whether a fiber optic cable plant is good one does a insertion loss test with a light source and power meter and compares that to an estimate of what is a reasonable loss for that cable plant.

Fiber optic coupler loss.

2x2 fused fiber optic couplers can split or mix light between two optical fibers with minimal loss and at a specified coupling ratio. Thorlabs couplers are available from stock in one of four ratios. 50 50 75 25 90 10 or 99 1. Coupling loss in fiber optics refers to the power loss that occurs when coupling light from one optical device.

For example with a 1 x 2 fiber optic coupler each output is less than one half the power of the input signal over a 3 db loss. Because of space requirements couplers may be routed in a way that causes enough bend loss to exceed the maximum loss for the channel. Coupling loss also known as connection loss is the loss that occurs when energy is transferred from one circuit circuit element or medium to another coupling loss is usually expressed in the same units such as watts or decibels as in the originating circuit element or medium. The difference between active and passive couplers is that a passive coupler redistributes the optical signal without optical to electrical conversion.

Star couplers with up to 32 ports have been possible using fused tapered fiber 3 db couplers. Fiber optic couplers can be either active or passive devices. The estimate called a loss budget is calculated using typical component losses for each part of the cable plant. Continued use of standard couplers splitters in a bend insensitive glass environment can nullify the bend loss reduction.

Real world fiber optic splitters show uniform performance across the whole spectrum of interest from 1260 to 1600 nm.