The Optical Kerr Effect operates on the principle that the refractive index \( n \) of a medium can be expressed as: \[ n = n_0 + n_2 I \] where \( n_0 \) is the linear refractive index, \( n_2 \) is the Kerr coefficient, and \( I \) is the intensity of the light. When a strong optical field is applied, the refractive index changes, thereby altering the phase velocity of the light. This can lead to phenomena such as self-focusing, self-phase modulation, and cross-phase modulation, which are crucial for various nanophotonic applications.
