Magneto-optic Crystal Polarization Controller Assisted Mode-Locked Fiber Laser

We report a passively mode-locked erbium-doped fiber laser based on a compact magneto-optic crystal polarization controller. The length of the polarization controller consisting of four magneto-optic crystal rotators and two quarter wave-plates is only 10 cm. Adjusting the polarization controller, central wavelength around 1559 nm and repetition rate 21.10 MHz mode-locked pulse are obtained. Pulse duration and 3 dB spectrum width are 598.4 fs and 6.24 nm respectively. Single pulse energy is about 151.7 pJ. Because of its small size, low insertion loss, good controllability and negligible dispersion, the magneto-optic crystal polarization controller could be an ideal polarization controller in fiber lasers.