Time delay in the mixed pump two-stage cascade erbium-doped fiber

Abstract

This thesis mainly focuses on the study of slow light under the mixed pump two-stage cascade erbium-doped fiber. Compared with previous studies, we adopt different pump optical fiber connections in structure and this structure can produce larger time delay. We specifically explore the relationship between modulation frequency, group velocity and time delay under different pump ratios. We find that the time delay gradually increases and the group velocity gradually decreases as the pump ratio M (M = P1480:P980) decreases. We also study length ratio and time delay at different frequencies. With the increase of length ratio N (N = L1:L2, L1 and L2 represent the length of the first and second cascaded optical fibers, respectively), the time delay all increases at different frequencies, and the time delay changes significantly at low frequencies.