Influence of modulation depth errors on properties of apodized chirped fiber Bragg grating property

Starting from the coupled mode equations, the influence of modulation depth errors on the properties of apodized chirped fiber Bragg grating(ACFBG) is investigated theoretically by using a matrix method. The results show that the errors of low frequency distribution deteriorate the performance of ACFBG much more than the errors of high frequency distribution with the same amplitude level, and the errors of higher amplitude level lead to more performance degradation. Therefore, errors of both low frequency distribution and high amplitude level should be avoided in the fabrication of the fiber grating.