Silicon nitride (SixNy) waveguides constitute a technology platform to realize optical signal processing based on the nonlinear Kerr effect. Varying the stoichiometry of the core (i.e., x and y in silicon nitride) provides an additional degree of freedom for engineering the waveguide properties, such as nonlinear Kerr parameter and dispersion. We demonstrate low-stress high-confinement silicon-rich nitride waveguides with flat and anomalous dispersion over the entire C and L optical wavelength transmission bands for optical signal processing based on cross-phase modulation. The waveguides do not show any nonlinear loss for a measured optical input intensity of up to 1.5 × 10 W/cm. In particular, we achieve wavelength conversion of 10 Gb/s signals across the C band; XPM broadening is also observed in the O band. In addition, we highlight the use of SixNy waveguides for nonlinear microwave photonics. Specifically, we demonstrate radio-frequency spectral monitoring of optical signals with a bandwidth of hundreds of gigahertz.
We demonstrate RF arbitrary waveform generation based on microwave photonic filtering. We use four-wave mixing in a silicon nanowire to increase the number of taps in an N-tap microwave photonic filter (MPF). Using a programmable optical filter, we can control the tap weights and, hence, the MPF response and corresponding generated waveform. We show uniform and apodized waveforms with four taps and seven taps with tunable central frequencies.
We propose and validate experimentally a time-delay to intensity mapping process based on second-order optical integrators. This mapping provides dynamic control of the intensity modulation profile of a waveform based on a purely passive and linear process. In particular, we can realize linear intensity control by tuning the time-delay between two optical pulses launched into a second-order optical integrator. We suggest and experimentally prove the use of this mapping process for reconfigurable optical arbitrary waveform generation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.