Self-tuning of a compact coupled-cavity APM fiber laser

Very stable, self-mode locked laser pulses have been generated spontaneously from all in-line coupled cavity (ILCC) fiber lasers studied, without the need of external length tuning, provided that three intracore Bragg gratings are perfectly matched. This is an unique property of the ILCC fiber laser comprising three distributed feedback Bragg gratings as cavity mirrors. Because the grating is sufficiently long (~l cm), the additive pulse mode locking (APM) action can always occur within a section of the distributed feedback length while allowing a self-adjusting of the phase of the circulating pulses between the coupled cavities