A systematic evaluation of Silicon-rich Nitride Electro-optic Modulator design and tradeoffs

TL;DR

This paper systematically evaluates silicon-rich nitride electro-optic modulators, analyzing their nonlinear properties, and demonstrates the feasibility of low-voltage, high-speed linearized phase modulation using CMOS-compatible materials.

Contribution

It provides a detailed analysis of third-order nonlinear effects and designs a linearized silicon-rich nitride phase modulator with promising VπLπ metrics.

Findings

Achievable VπLπ of 1 Vcm for phase modulators.

VπLπ as low as 0.5 Vcm in push-pull Mach-Zehnder configuration.

Linearized modulation enables high-speed operation with CMOS-compatible materials.

Abstract

We present a study of linearized \c{hi}^((3)) based electro-optic modulation beginning with an analysis of the nonlinear polarizability, and how to linearize a modulator based on the quadratic third order DC-Kerr effect. Then we perform a numerical study, designing a linearized \c{hi}^((3)) phase modulator utilizing Silicon-rich Nitride where we show that a phase modulator with a V_{\pi} L_{\pi} metric of 1 Vcm or a V_{\pi} L_{\pi} {\alpha} metric of 37VdB is achievable and a V_{\pi} L_{\pi} as low as 0.5Vcm in a push-pull Mach Zehnder Interferometer. This numerical study argues that linearized modulation exploiting the \c{hi}^((3)), and \c{hi}^((2)) as applicable, is possible and can allow for high-speed modulation using a CMOS compatible material platform.