100 GHz Bandwidth, 1 Volt Near-infrared Electro-optic Mach-Zehnder Modulator

TL;DR

This paper presents a hybrid thin-film lithium niobate electro-optic Mach-Zehnder modulator with over 100 GHz bandwidth and low voltage operation, suitable for high-speed near-infrared applications.

Contribution

It introduces a novel TFLN bonded to silicon nitride waveguides design that eliminates the need for TFLN etching, achieving ultra-broadband modulation at near-infrared wavelengths.

Findings

Bandwidth exceeds 100 GHz for the devices tested

Achieves a half-wave voltage length product of 0.8 V·cm at 784 nm

Demonstrates a bandwidth to voltage ratio of 100 GHz/V

Abstract

An integrated hybrid thin-film lithium niobate (TFLN) electro-optic Mach-Zehnder modulator (MZM) is shown at near-infrared wavelengths. The design uses TFLN bonded to planarized silicon nitride waveguide circuits, and does not require etching or patterning of TFLN. The push-pull MZM achieves a half-wave voltage length product ($V_\pi L$) of 0.8 V$.$cm at 784 nm. MZM devices with 0.4 cm and 0.8 cm modulation length show a broadband electro-optic response with a 3 dB bandwidth beyond 100 GHz, with the latter showing a bandwidth to half-wave voltage ratio of 100 GHz/V.