RECURSIVE SIMULATION-MODELS OF THE SEMICONDUCTOR-LASER MODULATION CHARACTERISTICS FOR ACCURATE PERFORMANCE EVALUATION OF COHERENT OPTICAL CPFSK SYSTEMS

Modeling of the semiconductor laser nonuniform FM response and residua l IM modulation is essential for the computer-aided design of coherent optical communication systems, This paper presents an accurate simula tion model, in which the FM and IM responses are represented by recurs ive digital filters derived directly from measurements, A comparison w ith previous models of the bibliography reveals the advantages of the current approach, The proposed modeling procedure is applied in the ca se of a single-electrode DFB laser, This DFB model, in combination wit h a semi-analytical technique for the evaluation of the error probabil ity, is used to study the influence of the modulation characteristics on the performance of a coherent heterodyne CPFSK system with differen tial receiver operating at 1 Gb/s, Theoretical and experimental result s are in excellent agreement.