Which of the following is a characteristic of single-mode fiber?

Single-mode fiber is designed with a very thin core, typically around 8 to 10 microns in diameter, which allows only a single mode of light to propagate through the fiber. This design reduces the amount of signal attenuation and enables longer transmission distances compared to multi-mode fiber.

The ability to support longer distances with less signal loss is a fundamental advantage of single-mode fiber, making it particularly suitable for applications that require high bandwidth over long distances, such as in telecommunications and data centers. This characteristic is primarily due to the lower levels of dispersion that occur in single-mode fibers, which is a result of having only one light path, thus minimizing signal distortion and maintaining the integrity of the data being transmitted.

In contrast, multi-mode fibers, with their larger core diameter (typically around 50 or 62.5 microns), allow multiple light modes to propagate, which results in modal dispersion over long distances. This phenomenon can lead to increased signal loss and limits the effective range of multi-mode fiber systems.

The cost difference between single-mode and multi-mode fiber, as well as the issues with core diameter and modal dispersion, further illustrate why the correct characteristic of single-mode fiber is its capability to support longer distances with less signal loss.