What aspect of optical fibers does cladding primarily enhance?

Cladding plays a crucial role in the functionality of optical fibers by enhancing light retention and facilitating total internal reflection. When light travels through the core of an optical fiber, it encounters the cladding layer that surrounds it. The refractive index of the cladding is lower than that of the core, which allows light signals to be kept within the core by reflecting off the core-cladding boundary, provided the angle of incidence is appropriate. This process ensures that the light signals can travel long distances without significant loss, maintaining the integrity and strength of the signal.

The other choices focus on different properties of the fiber that are important but are not directly improved by cladding. For instance, while cladding can contribute to the overall durability of the fiber, it is not its primary enhancement feature. Resistance to environmental factors can also be a concern, but it involves factors like the material and protective coating rather than cladding specifically. Lastly, while signal bandwidth is essential for transmission capacity, it is influenced more by the core's material and design than by the cladding itself.