Soliton Molecules with Two Frequencies

We demonstrate a peculiar mechanism for the formation of bound states of light pulses of substantiallydifferent optical frequencies, in which pulses are strongly bound across a vast frequency gap. This isenabled by a propagation constant with two separate regions of anomalous dispersion. The resulting solitoncompound exhibits moleculelike binding energy, vibration, and radiation and can be understood as amutual trapping providing a striking analogy to quantum mechanics. The phenomenon constitutes anintriguing case of two light waves mutually affecting and controlling each other.