The Bragg reflection characteristics of the fibre grating formed by chirped ultrashort laser pulses
啁啾飞秒激光脉冲形成的光纤光栅的Bragg反射特性

Under the illumination of 800 nm femtosecond laser pulse, two photon absorption phenomenon can occur in the photosensitive glass As 2S 3. When a chirped femtosecond laser pulse meets with another femtosecond laser pulse in an As 2S 3 fibre, the interference pattern can be recorded permanently as a chirped grating. In this paper, the relation between the structure of the chirped fibre grating and the parameters of the incident femtosecond pulse is described. Numerical calculations show that the chirped fibre grating has a broad Bragg reflection spectrum.