Linear Dual-Series Mach Zehnder Modulator Employing Electrostatic Doping for Photonic Integrated Circuits

Abstract

In this paper, we propose a highly linear electrostatic doping (ED) assisted dual series Mach-Zehnder modulator (MZM) suitable for photonic integrated circuits (PICs). A complete simulation study on the performance of the proposed dual series MZM is incorporated in this paper. We have analytically formulated the steady-state and the nonlinear performance of the proposed modulator and the simulation results using commercial grade photonic circuit simulator are also incorporated in support of the analytical study. Simulation results show that the proposed modulator can offer <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\sim\!\!16$</tex-math></inline-formula> dB of static extinction ratio (ER) with 3.2 dB of insertion loss (IL). The modulator offers approximately 10.2 dB of dynamic ER at 10 Gb/s data rate. The effect on the transfer function of the dual-series MZM due to the imbalance in the driving RF signals is also discussed supported with simulation results. The nonlinear performance of the proposed modulator is also estimated using analytical method and dual-tone test method. Results indicate that the spurious free dynamic range (SFDR) of the proposed dual series MZM for second and third order intermodulation distortions (IMD2 and IMD3) are 96.11 dB.Hz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{1/2}$</tex-math></inline-formula> , and 132.4 dB.Hz <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{2/3}$</tex-math></inline-formula> , respectively. Study of the transient performance also reveals that the 3-dB electro-optic bandwidths are 11.39 GHz and 8.32 GHz for single and dual-series ED-assisted MZM, respectively.