Ultrashort light bullet solutions in dual-core dispersion-decreasing media

The ultrashort light bullet solutions to a (3+1)-dimensional generalized nonlinear Schrodinger equation with inhomogeneous coefficients and a varying source are obtained. This model can describe the wave propagation in the dual-core dispersion-decreasing media. Two types of dispersion, the hyperbolic and the Gaussian profiles, are discussed in the media to show the different propagation properties of light bullet solutions. We find that the chirp parameter can control whether the solution is broadened or compressed, and the light bullet solutions in the dispersion-decreasing media with Gaussian profile can be compressed to a predictable degree. Our results may be useful to the pulse compression in dual-core diffraction-decreasing media when associate with the generation of ultrashort pulses.