Integrated lithium niobate intensity modulator on a silicon handle with slow-wave electrodes

TL;DR

This paper presents a high-speed, integrated lithium niobate intensity modulator on a silicon handle with segmented electrodes, achieving high bandwidth and low voltage operation without substrate removal, suitable for silicon foundries.

Contribution

It introduces a novel integrated modulator using a silicon handle with segmented electrodes, eliminating the need for substrate removal and enabling scalable manufacturing.

Findings

Bandwidth of 95 GHz at 3 dB

Half wave voltage of 3.75 V

Extinction ratio of 45 dB

Abstract

Segmented, or slow-wave electrodes have emerged as an index-matching solution to improve bandwidth of traveling-wave Mach Zehnder and phase modulators on the thin-film lithium niobate on insulator platform. However, these devices require the use of a quartz handle or substrate removal, adding cost and additional processing. In this work, a high-speed dual-output electro-optic intensity modulator in the thin-film silicon nitride and lithium niobate material system that uses segmented electrodes for RF and optical index matching is presented. The device uses a silicon handle and does not require substrate removal. A silicon handle allows the use of larger wafer sizes to increase yield, and lends itself to processing in established silicon foundries that may not have the capability to process a quartz or fused silica wafer. The modulator has an interaction region of 10 mm, shows a DC half wave voltage of 3.75 V, an ultra-high extinction ratio of roughly 45 dB consistent with previous work, and a fiber-to-fiber insertion loss of 7.47 dB with a 95 GHz 3 dB bandwidth.