Soliton annihilation and fusion from resonant inelastic collisions in birefringent optical fibers

We study the inelastic collisions between orthogonally polarized solitons in a birefringent optical fiber. We show that if the collision is sufficiently slow, one soliton may be destroyed by the other, or the two solitons may fuse into a breatherlike solitary pulse. We derive a simple analytical estimate for this soliton decay, based on a condition of spatial resonance between the two solitons, and confirm this prediction by numerical simulations. Breakup of colliding solitons with different polarizations may set a fundamental lower bound to the soliton time width in soliton transmissions.