%0 Journal Article %T Exploring Gravitational Soliton %A Bi Qiao %J Journal of Modern Physics %P 594-612 %@ 2153-120X %D 2025 %I Scientific Research Publishing %R 10.4236/jmp.2025.164032 %X This paper constructs a four-dimensional gravitational soliton solution that strictly satisfies Einstein’s vacuum field equations, revealing the intrinsic connection between strong-field nonlinear gravity and weak-field linear theory, and proposes a nonlinear unified mechanism for electromagnetic-gravitational interaction. Based on light-cone coordinates and transverse plane polarization structures, a metric form with a sech 2 ( ku ) type envelope is developed, and its waveform stability is shown to arise from the dynamic balance between nonlinear self-interaction terms and spacetime dispersion effects. The study demonstrates that in the weak-field limit, the soliton degenerates into linear gravitational waves, whose polarization mode h ij =A ϵ + +B ϵ × strictly corresponds to a spin-2, zero-mass graviton, indicating that gravitons are essentially low-energy approximations of nonlinear fields. Further, through the generalized gauge transformation theory, it is shown that two electromagnetic optical solitons in the strong-field region can nonlinearly couple into a gravitational soliton. This process degenerates in the weak-field limit to photon-graviton conversion, supporting the gauge symmetry unification of electromagnetic and gravitational interactions. Additionally, it is predicted that the characteristic waveform of the soliton (such as the sech 2 envelope and the absence of high-frequency cutoff spectra) may generate signals in high-energy astrophysical events that differ from linear gravitational waves, providing a new target for future gravitational wave detection. This work establishes for the first time a strict generalized gauge transformation relationship between solitons, gravitons, optical solitons, and polarized photons, offering an exploratory paradigm for the unified theory of strong-field gravity and electromagnetism. %K Gravitational Soliton %K Einstein Equation %K Gauge Transformation %K Graviton %K Dual Photon %K Nonlinear Effects %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=142220