Suppression of external cavity modes in DFB lasers with a high endurance against optical feedback

This paper clarifies that the external cavity modes deform optical output response in the DFB lasers by enhancing the relaxation oscillation under NRZ modulation. It is shown that a DFB laser with an asymmetric structure in reflectivity of facets and in position of a /spl lambda//4 phase shift can suppress the influence of the external cavity modes.<
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