Low-Vπ, coupling-optimized, single-ended push-pull ring-assisted Mach-Zehnder modulators for integration with high-speed, low-swing voltage drivers in integrated silicon-photonic platforms

Silicon (Si) photonic integrated circuits (PICs) allow for the combination of high-speed Si electronics with integrated photonic components on a single chip. However, integrated photonic modulator designs are often limited by the driving electronics since, modulators often require large voltage swings from high-speed electrical driving circuits. Due to inherent gain-bandwidth trade-offs, creating high-speed voltage drivers with large voltage swings is difficult without considerable design effort. The use of Ring-assisted Mach-Zehnder Modulator (RA-MZM) schema allows for compact modulator design while decreasing Vπ, resulting in less restrictive driving voltage requirements. Electronic requirements can be further reduced by employing a single-ended push-pull scheme for the RA-MZMs and exploiting intentionally over- and under-coupled RA-MZM designs targeting phase or amplitude cancellation operation. RA-MZM design optimization allows for more lenient voltage swing design requirements at the electronic-photonic interface, facilitating modulation at higher speeds while still preserving data fidelity.