Widely Spaced Bound States in a Soliton Fiber Laser With Graphene Saturable Absorber

Highly coherent two-soliton loosely bound states with pulse separation of two orders of magnitude of pulse width are generated by delicate control of initial conditions in a soliton fiber laser using a graphene mode-locker. It represents the most widely spaced bound state directly obtained in fiber lasers as far as overlap of two intracavity solitons is concerned.