Optical Microwave Waveforms Generation Based on the Round-Trip Phase of the DFB Laser

In this paper, we theoretically and experimentally analyze the influence of round-trip phase distributed feedback (DFB) lasers on harmonic-phase photocurrent, caused by external injection current. The results indicate that photocurrent introduced (HPIRP) reduces with increase modulation depth at a fixed frequency. Then, based HPIRP DFB laser, simple photonic generation method optical microwave waveforms is proposed verified. scheme, three different wavelengths are mainly used. By adjusting tunable delay lines attenuators, amplitude branches converted photodetector (PD) can be controlled individually. superposition properly to form target waveform. Dispersive elements complex filtering not required. Through experiments, rectangular triangular repetition frequency 3.75 GHz generated.