A simplified modal method to explain the resonance phenomenon in guided mode resonance (GMR) gratings with asymmetric coatings is presented. The resonance observed is due to the interaction of two propagation modes inside the grating. The reflectivity spe
Channel spacing halving and multi-channel apodisation of sampling fiber Bragg grating (SFBG) based on moire effect are demonstrated, which are realized by stretching and double exposure in fabrication of the SFBG. The experiment and theoretical analysis s
We report a high power fiber amplifier based on nonlinear chirped-pulse amplification (NCPA). To manage the nonlinearity, pulse shaping is introduced by self-phase modulation in the fiber stretcher with the help of spectral filtering. The third-order disp