Photonic generation of microwave waveforms based on a dual-loop optoelectronic oscillator

A novel photonic scheme of microwave waveforms generator based on a dual-loop optoelectronic oscillator (OEO) is experimentally verified. A 10-GHz microwave signal generated by OEO is modulated onto the directly modulated laser (DML) and the phase modulator (PM) simultaneously. By adjusting the driven power of the DML and the PM and the phase difference between the pulse signal inputted into the PM and the PM's driven signal, the desired optical spectrum is obtained. By passing appropriate dispersion, the optical spectrum can be converted into desired waveform. In this experiment, a series of waveforms with the shapes of sawtooth/reversed-sawtooth, triangle, and pulse are generated.