Research On All-Optical Flip-flop Based On Fabry-Perot Laser Diode

All-optical flip-flop (OFF) is an optical logic device with memory function and can be assembled to provide such functions as clock recovery, clock regeneration, header extraction, header recognition and optical buffering utilized in high all-optical signal processing systems. It will play an important role in the All-optical-net. The current research on all-optical flip-flops is still in its early stage now and lots of technologies have been considered as a candidate of all-optical flip-flop.In this paper, a novel scheme is proposed and experimentally demonstrated for all-optical flip-flop based on the optical bistability of an injection locked Fabry-Perot laser diode (FP-LD). Firstly, the experimental studies are respectively demonstrated on injection locked laser, self-seeding, optical bistability. And then an all-optical flip-flop is assembled with one FP-LD and two Fiber-Bragg-Gratings (FBG) external cavity. The All-optical flip-flop operation can be realized using optical bistablility to maintain the output state of OFF. The essential part to obtain bistability in this system is that lasing light output of FP-LD is fed back partly by two FBGs at certain wavelengths. The EDFA was used to adjust the power of feedback light. The on or off state of the All-optical flip-flop is determined by the set or reset light externally at different wavelength. The all-optical flip-flop operated at the wavelength of 1537nm with a on-off contrast ratio of 15 dB.The advantage of the all-optical flip-flop is its simple structure and can be integrated easily.To our knowledge, it is the first time to experimentally demonstrated all-optical flip-flop operation using a fiber grating external cavity, and the model has important guidance meaning and reference value to the future research of All-optical flip-flop.