Interferometric Coupling-based Modulator for Large-Scale Integrated Photonic Systems

Integrated photonics, an emerging branch of photonics in micron-scale proximity, has drawn tremendous attention due to its capability for the generation, manipulation and detection of optical signals on a single chip. Microring modulators (MRMs) and Mach-Zehnder modulators (MZMs) are two frequently used photonic devices in modern electro-optic communications that also play an important role in the development of photonic computing systems [1] , [2] . However, their modulation technique which is based on operational wavelength-peak drift may cause optical crosstalk when one of the peaks moves towards an adjacent peak, especially in a large-scale optical system. Consequently, the optical modulation amplitude (OMA) of the adjacent peak reduces. This limits the implementation scale of an integrated system based on multiple cascaded modulators. It has been reported that an optimized MRM design could support up to 108 wavelength division multiplexing (WDM) channels [3] .