The dynamics of optical pulses in noninstantaneous Kerr media are considered. It is found that the “mass center” of the localized profile exhibits an accelerated transversal (on the time axis) motion during propagation. In the highly noninstantaneous regime, especially, the motion can approximately be uniformly accelerated up to one dispersion length, which is also proportional to the ratio between the pulse power and the relaxation time of the media. The evolutions of the pulse width and chirp are also investigated. An interesting phenomenon is found: the nonlinearity-induced chirp in the highly noninstantaneous regime is the “inverted image” of the pulse shape. Based on the acceleration property of the transversal motion, the existence of soliton-like solutions in the noninstantaneous Kerr system is also discussed. It is found that the highly noninstantaneous Kerr system has no soliton-like solutions.

• Received 26 November 2014
• Revised 23 June 2015

DOI:https://doi.org/10.1103/PhysRevA.92.023803