The fabrication mechanism and spectral characteristics of Fiber Gratings fabricated by point by point direct writing based on femtosecond laser pulses
In this paper, a series of fiber gratings with different spectrum characteristics are fabricated in standard telecommunication fiber without hydrogen loading by point by point direct writing method based on 100 femtosecond laser amplifier system at 800 nm central wavelength. They are including the fourth order fiber Bragg grating, fiber Bragg grating Fabry Perot cavity, sampling fiber Bragg grating and cascaded long period fiber grating. The experimental results show that the spectrum characteristics of fourth order fiber Bragg gratings with L=1.93 mm period are obtained at the center wavelength l=1394.5 nm, and the fiber Bragg grating Fabry Perot cavity can be inscribed when the gating period is L=1.95 mm. Furthermore, the sampled fiber Bragg gratings with different sampled periods are fabricated by adjusting the sampling period. Finally, the spectrum of the cascaded long period fiber gratings is achieved by changing the grating pitch of long period grating with 3 mm, 5 mm and 7 mm, respectively. This study will provide a powerful experimental gist and theoretical basis for the fabrication of different types of fiber gratings by femtosecond laser point by point writing directly method.
2019 18th International Conference on Optical Communications and Networks (ICOCN)