Study on High-Speed Directly Modulated DFB Lasers Based on Detuned Loading and Photon-Photon Resonance Effects

Abstract A monolithic integrated two-section distributed feedback (TS-DFB) semiconductor laser for high-speed direct modulation is proposed and theoretically analyzed. The grating structures of the TS-DFB laser are designed by the reconstruction-equivalent-chirp (REC) technique, which can reduce the manufacturing cost and difficulty, and achieve high wavelength controlling accuracy. The detuned loading and photon-photon resonance (PPR) effects are utilized to enhance the modulation bandwidth of the TS-DFB laser, which can exceed 37 GHz. While that of the conventional one-section DFB laser is only 16 GHz. The clear eye diagrams with large open extents can still be obtained when the bit rate of the non-return-to-zero (NRZ) signal reaches 55 Gb/s. These results show that the proposed method can enhance the modulation bandwidth of DFB laser significantly.