What characterizes a laser with a non-linear response compared to linear optical fibers?

A laser with a non-linear response is characterized by a variable index of refraction. In non-linear optics, the properties of an optical medium change in response to the intensity of the light passing through it. As the intensity increases, the refractive index of the medium can vary, leading to various phenomena such as self-focusing, Kerr effects, and multi-photon absorption.

This characteristic is fundamentally different from linear optical fibers, where the refractive index remains constant regardless of the light intensity. In linear systems, the relationship between light intensity and refractive index is straightforward and does not involve the complexities introduced by intensity-dependent changes.

Having a variable index of refraction allows lasers and nonlinear materials to achieve novel effects that enhance certain applications, such as optical switching, frequency conversion, and the generation of new wavelengths. This variability can lead to improved performance in specific applications, distinguishing non-linear lasers from their linear counterparts.