Optical Fourier synthesis of high-repetition-rate pulses

The ultimate goal in the generation of optical signals is optical arbitrary waveform generation, which would allow the generation of wide-bandwidth optical signals with arbitrary amplitude and phase profiles (e.g., custom-shaped short optical pulses or advanced telecommunications signals). Here we investigate a new route toward this goal based upon the coherent combination of multiple signals generated at different wavelengths from different lasers. We show how to address the various challenges associated with this approach and demonstrate the generation of 100 GHz repetition rate waveforms by combining five semiconductor lasers phase locked, via injection locking, to a common optical frequency comb. Independent control of the optical power and phase of each laser enabled the generation of customized waveforms. Our technique be should readily scalable to a larger number of lasers, promising a flexible source of ultrastable, high-repetition rate, large-bandwidth (>1 THz), shot-noise-limited, high-power optical waveforms.