High-Speed Pulsed Fiber Ring Laser Using Photonic Crystal Fiber

In this paper, we propose and experimentally demonstrate a mode locked fiber ring laser with the implementation of a photonic crystal fiber (PCF) to generate pulse train at high speed. This fiber ring laser combines rational harmonic mode locking based on a Lithium Niobate Mach-Zehnder modulator and nonlinear polarization rotation from a highly nonlinear PCF. By fine tuning of the modulation frequency and the polarization controllers in the cavity, a 30 GHz pulse train with pulse width 1.9 ps is generated. Without the PCF, the pulse width at 30 GHz from the rational harmonic mode locking is 5.8 ps. We also conduct numerical simulations of the pulse evolution, which shows good agreements of the experimental results.