This Small Business Innovation Research Program (SBIR) Phase I project advances arbitrary waveform generation (AWG) capabilities for high bandwidth operation essential in technologies such as telecommunications, test and measurement, remote sensing, and others where higher bandwidths are demanded but cannot be achieved with current electronic devices. This new innovation employs an optical fiber storage ring to interferometrically combine many low-bandwidth input waveforms to synthesize high-bandwidth output waveforms. This technology exploits advances in stable fiber lasers and telecommunications components with hardware comprised of commercial off-the-shelf photonics and low-bandwidth electronics. Prior efforts have successfully demonstrated the device concept and led to one patent pending. This SBIR project addresses fundamental coherence issues through device-engineering that enables bandwidth extension above 25 GHz, and noise reduction in the photonic components, moving this innovative solution towards a viable commercial product. Metrics for success are combined bandwidth, time aperture, and signal fidelity. This photonic method for wideband AWG offers the potential for high bandwidth (>100 GHz), long waveform durations (>10 microseconds), with high fidelity (40 dB SFDR). The broader impact/commercial potential of this project offers the potential for transformative advances in full utilization of the electromagnetic spectrum spanning microwave to terahertz frequencies. In particular, this approach is ideally suited to bridge the technological gap that exists between waveform generation by well-developed continuous AM or PM modulation of individual coherent sources and by proposed methods of controlled synthesis of frequency arrays. This technology provides a unique combination of high spectral resolution, long time aperture, and high bandwidth that has broad application in test and measurement devices, telecommunications, signal processing, and next-generation information technologies that exploit the full information capacity of optical fiber beyond the current capabilities. Generation of agile, complex, wideband optical waveforms can enable new paradigms for free space optical communications, while also applicable to spread spectrum and low probability of intercept applications. This project also aims to investigate fundamental noise issues inherent to repeated re-amplification of coherent optical signals, providing insights directly relevant to meeting the rapidly increasing needs of our modern information age. Furthermore, the coherent optical storage ring technology developed in this project will benefit a number of other potential applications such as wideband spectrum analysis and ultra-high precision characterization of optical oscillators
