Bidirectional coupling of two erbium-doped fibre ring lasers subject to sine-wave pump modulation

摘要

Two erbium-doped fibre ring lasers are subject to different sine-wave pump modulation conditions, so that each of them may present periodic or chaotic response. For each working condition, the response of both lasers is analyzed for different coupling factors of their cavities. Many possible situations are found: as the coupling factor is swept from 0 to the maximum coupling allowed by the setup, for some modulation conditions no change of regime (periodic or chaotic) is observed, while in other cases the regime changes several times. Besides, it is found that the correlation between both laser emissions may not increase monotonously with the coupling factor: for certain intermediate coupling values, a correlation minimum is found. Nevertheless, a similar feature of all cases is the coupling ratio necessary to achieve a synchronized behaviour: it does not depend strongly on the modulation conditions chosen. The experimental results are compared with numerical simulations. An acceptable agreement is obtained.