High-efficiency PAM4 ring modulator using W-Shaped PN junction

Abstract

A novel approach in designing the ring modulator’s PN junction doping profile was proposed, where a W-shaped profile was used and compared to the conventional lateral profile, with the aim of achieving better performance and higher extinction ratios. Simulations were performed in the C-band on the 50GBd/s PAM4 ring modulator in the case of lateral doping profile and the case of the demonstrated approach of using a W-shaped doping profile. The results demonstrate how the implementation of the W-shaped profile introduces a significant 2.3x enhancement in the wavelength shift per unit voltage compared to its lateral counterpart, at the same doping levels, with lower losses and bandwidth. The demonstrated results show the effect of changing the doping profile on the performance of the ring modulator and its potential in making highly efficient optical modulators that can fulfil the growing market requirements.