Direct-Digital-Drive Microring Modulator

TL;DR

This paper introduces a digital drive method for microring resonators, enabling high-resolution digital-to-analog conversion and complex modulation schemes like M-QAM through digital linearization and segmented electrodes.

Contribution

It presents a novel digital drive approach for microring modulators, achieving high ENOB and EVM performance in simulation, and enabling advanced digital modulation formats.

Findings

A 4-bit DAC achieves 3.74 bits ENOB in simulation.

A 16-QAM modulator achieves EVM better than -30dB.

The method enables digital control of microring resonators for high-performance optical modulation.

Abstract

The method of Direct Digital Drive is applied to a microring resonator. The microring resonator is thus controlled by a segmented set of electrodes each of which is driven by binary (digital) signal. Digital linearization is performed with the aid of digital memory lookup table. The method is applied to a single microring modulator to provide an M-bit digital-toanalog converter (DAC), which may also be viewed as an M-level pulse amplitude modulator (M-PAM). It is shown, by means of simulation, that a 4-bit DAC can achieve an effective number of bits (ENOB) of 3.74bits. Applying the same method for two rings, enables the generation of two-dimensional optical M-QAM signals. It is shown, by means of simulation, that a 16-QAM modulator achieves an EVM better than -30dB.