How does a non-linear fiber generally respond to varying light intensity?

A non-linear fiber exhibits a unique property where its refractive index changes in response to varying light intensity. This phenomenon is due to the non-linear optical effects that occur within the material of the fiber. When the intensity of light traveling through the fiber changes, the refractive index also changes, which allows for various applications in telecommunications and signal processing.

In simple terms, as more light (higher intensity) is introduced into the fiber, it can cause the refractive index to increase or decrease based on the specific properties of the fiber material and the wavelength of the light being used. This responsiveness is the basis for many non-linear optical effects such as self-phase modulation and four-wave mixing, making these fibers suitable for advanced uses like supercontinuum generation or optical signal processing.

The other options do not accurately describe the behavior of non-linear fibers. For example, non-linear fibers do not absorb all light equally; they have a unique response based on intensity rather than a uniform absorption profile. Moreover, a fixed index of refraction does not characterize non-linear fibers because their index varies with light intensity. Lastly, while enhanced light transmission can occur under certain conditions, it does not fundamentally define the behavior of a non-linear fiber in response to varying light intensity as the modification