AFRL-AFOSR-VA-TR-2015-0365 Silicon-Chip-Based Optical Frequency Combs

We have theoretically and experimentally investigated the dynamics of frequency comb generation insilicon-based microresonators. In this system, the parametric gain associated with the nonlinear process offour-wave mixing leads to parametric oscillation and generation of signal/idler sidemodes.This report describes our results that further develop the parametric comb technology. We theoreticallyinvestigate comb generation and modelocking dynamics, and the connection to concepts ofsynchronization and self-organization. We also investigated mode-crossings in microresonators andtunable coupling, and their impact on comb formation. We studied comb generation without an externalpump laser. In addition, we explored comb generation at other pump wavelengths using dispersionengineering. Finally, we investigated comb generation via coherent supercontinuum generation in siliconnitride waveguides. Our research effort illustrates that the silicon-based platform offers a high potential as a platform for robust,integrated, chip-scale comb source. Since the dispersion of the system can be readily tailored throughwaveguide cross-section engineering, the platform offers flexibility in operating wavelength and bandwidth.The developments made here are a significant step towards the development of chip-based frequencycombs that can operate in real-world sensing and spectroscopy, for optical clocks, and for frequency metrology applications. Distribution Statement This is block 12 on the SF298 form. Distribution A Approved for Public Release Explanation for Distribution Statement If this is not approved for public release, please provide a short explanation. E.g., contains proprietary information.