Millimeter wave frequency generation based on variations in coupling coefficients of a silicon add-drop microring resonator

Abstract

A microwave photonic system with silicon add-drop microring resonator as the core photonic device is analyzed for microwave/millimeter wave frequency generation. The primary concept of the proposed study relies on varying the coupling coefficients of the silicon add-drop microring resonator. Unequal coupling coefficients between the ring cavity and bus waveguides are one of the parameters which are responsible for generating second, third order sidebands in the radio frequency spectrum generated at the photodetector. Another parameter of interest is the phase difference between the two radio frequency signals which are fed to the Mach–Zehnder modulators of the proposed system. A 1 GHz sinusoidal signal with 1V peak-to-peak amplitude results in a third order sideband generation whose frequency corresponds to 3 GHz. The coupling coefficients in this case are 0.2 and 0.8, between ring cavity, top and bottom waveguides respectively. It is also observed that, phase difference of 90◦ between the input radio frequency signals results in highest power of the third order sideband generated in the output radio frequency spectrum whose frequency corresponds to the multiple of input radio frequency.