啁啾飞秒激光脉冲形成的光纤光栅的Bragg反射特性

The Bragg reflection characteristics of the fibre grating formed by chirped ultrashort laser pulses

在 8 0 0nm飞秒脉冲激光照射下光敏玻璃As2 S3光纤具有双光子吸收现象 ,当一束超短激光脉冲与另一束啁啾超短激光脉冲在As2 S3光纤相遇时 ,干涉图案将永久地记录一个空间啁啾光栅 .研究了该光栅结构与入射超短脉冲激光脉冲参数的关系 ,数值计算表明该光栅具有较大的Bragg反射带宽 .

Under the illumination of 800 nm femtosecond laser pulse, two-photon absorption phenomenon can occur in the photosensitive glass As2S3. When a chirped femtosecond laser pulse meets with another femtosecond laser pulse in an As2S3 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.