Toward a photonic arbitrary waveform generator using a modelocked external cavity semiconductor laser

We propose an architecture for photonic arbitrary waveform generation where the phase-locked longitudinal modes of a 12.4-GHz fundamentally modelocked external cavity semiconductor laser are individually modulated. We report photonic synthesis of microwave tones at 37.2 GHz (limited by photodetector bandwidth) with linewidth < 100 Hz and dynamic range 50 dB at 100-Hz resolution bandwidth. We show photonically synthesized 12.4-GHz sine waves with superimposed sinusoidal and pulsed RF modulations, demonstrating the potential for photonic arbitrary waveform generation with the proposed architecture.