Self-Tuning Mode-Locked Fiber Lasers Based on Prior Collection of Polarization Settings

We present a method to discriminate stable mode-locked states of an all fiber erbium-doped laser based on nonlinear polarization rotation mechanism. The method has a balance between the accuracy and rapidness of the pulses discrimination. Mode-locked states are distinguished and confirmed by an amplitude discriminator, which reflects the repetition rate information of the pulses. An electronic polarization controller is used to precisely adjust the intracavity polarization states. The driving voltages of the electronic polarization controller at those mode-locked states are recorded as populations, and it is benefit to reduce the build-up time for mode locking. The populations are also recorded at operation temperature covering from 20 °C to 50 °C, which exhibits the repeatability and stability of the mode-locked states. Rapid self-tuning mode-locked fiber lasers could be achieved by the repeatability of the polarization settings under the stable temperature environment.