In this work an all-fiber linearly-polarized Yb-doped double-clad fiber laser is proposed, in which the resonance cavity is
composed of a pair of polarization maintaining fiber Bragg gratings (PM-FBGs). The polarization hole burning is
enhanced by the selective polarization feedback by the PM-FBGs. A three-port polarization beam splitter with fiber
pigtail was inserted into the laser cavity to select different polarization states. The laser features wavelength of 1069.72
nm and 1069.98 nm, output power of 125 mW, SNR of 45 dB, slope efficiency of 52%, as well as linewidth of 30.7 pm.
The polarization characteristics of the laser are studied by measuring the laser power transmitted through a rotating Glan-
Thomson polarizer. The degree of polarization of each lasing line is over 12 dB under different pump levels.
This paper investigates the performances of 16×100Gbit/s return-to-zero differential quadrature phase shift keying (RZDQPSK)
coded modulation signals in dense wavelength division multiplexing (DWDM) system and compares three
different dispersion compensation fiber (DCF) methods. The performance has been evaluated by using Q value as the
major parameter along with the variation of the input power for different channels with different dispersion
compensation schemes. It is observed that symmetrical compensation of DCF is more excellent than pre-compensation
and post-compensation methods. Corresponding to symmetrical compensation of DCF method, the maximum values of
Q factor are 11.7026, 10.5128 and10.5138 for channel NO.1, channel NO.8, and channel NO.16, respectively.
Meanwhile, the eye diagram shape of symmetrical compensation method is superior to the others.