%0 Journal Article %A R. Z. R. R. Rosdin and N. M. Ali and S. W. Harun and H. Arof %D 2014 %J International Journal of Physical and Mathematical Sciences %B World Academy of Science, Engineering and Technology %I Open Science Index 96, 2014 %T Bright–Dark Pulses in Nonlinear Polarisation Rotation Based Erbium-Doped Fiber Laser %U https://publications.waset.org/pdf/10000029 %V 96 %X We have experimentally demonstrated bright-dark pulses in a nonlinear polarization rotation (NPR) based mode-locked Erbium-doped fiber laser (EDFL) with a long cavity configuration. Bright–dark pulses could be achieved when the laser works in the passively mode-locking regime and the net group velocity dispersion is quite anomalous. The EDFL starts to generate a bright pulse train with degenerated dark pulse at the mode-locking threshold pump power of 35.09 mW by manipulating the polarization states of the laser oscillation modes using a polarization controller (PC). A split bright–dark pulse is generated when further increasing the pump power up to 37.95 mW. Stable bright pulses with no obvious evidence of a dark pulse can also be generated when further adjusting PC and increasing the pump power up to 52.19 mW. At higher pump power of 54.96 mW, a new form of bright-dark pulse emission was successfully identified with the repetition rate of 29 kHz. The bright and dark pulses have a duration of 795.5 ns and 640 ns, respectively. %P 1461 - 1464