What principle does an OTDR utilize to analyze fiber optics?

An OTDR, or Optical Time-Domain Reflectometer, employs the principle of wave propagation to analyze fiber optic cables. It sends a pulse of light into the fiber and measures the intensity of light that is reflected back to the source over time. The device interprets the reflections based on the time it takes for the light to return, which helps identify faults, splices, and connectors along the fiber.

Using wave propagation principles allows the OTDR to assess the distance to any discontinuities in the fiber, as changes in the medium will reflect varying amounts of light. This principle is fundamental to understanding how light travels through the fiber and provides important data on the cable's integrity and overall performance.

The other options, while related to the behavior of light in fiber optics, do not capture the specific operational mechanism of an OTDR. Refraction of light deals primarily with the bending of light as it passes through different materials, while the breakdown of optical signals refers to potential failures in the transmission itself, rather than the measurement technique used by the OTDR. The fusion of fiber ends pertains to the physical process of joining fibers, rather than the analytical method the OTDR employs.