Photonic-electronic arbitrary-waveform generation using quadrature multiplexing and active optical-phase stabilization

Generation of electrical waveforms with bandwidths of 100 GHz or more is key to many applications in science and industry, comprising high-speed communications, radar, or test and measurement equipment. However, while conventional digital-to-analog converters based on electronic circuits still represent the technological mainstay for broadband waveform generation, further bandwidth scaling comes with a series of challenges related to circuit design and implementation, packaging, and system integration. In this paper, we show that photonic-electronic signal-processing techniques may overcome these limitations. We demonstrate a photonic-electronic waveform generator that exploits quadrature multiplexing in the optical domain in combination with phase-stabilized coherent down-conversion to the electrical domain. In a proof-of-concept experiment, we generate electrical multi-level data signals at symbol rates up to 200 GBd at quality levels that can already compete with best-in-class electronic systems. We believe that our concept opens an attractive path to waveforms generation at bandwidths beyond the limitations of current microelectronics, leveraging advanced photonic integration technologies that are currently being developed.