What type of loss is indicated by a drop of energy represented as a step in the middle of a graph?

The indicated type of loss represented as a step in the middle of a graph is splice loss. Splice loss occurs at a location where two fibers are joined together through splicing. This can happen due to misalignment, differences in the core diameter, or the refractive indices of the two fibers being spliced.

In a graphical representation of the power level, a step drop reflects the sudden decrease in power that happens at the splice point, as energy is lost due to the inefficiencies of the splice. Understanding splice loss is critical as it highlights the importance of proper splicing techniques to minimize loss and ensure efficient transmission of optical signals over fiber networks.

The other options do not accurately describe this type of loss. The initial pulse refers to the first signal sent through the fiber and does not depict an energy drop over distance. Absolute power is a measure of power in watts but does not specifically indicate loss. Fiber size relates to the diameter of the fiber optics and does not directly concern loss indicated on a graph.