2026 · 01· Nature Communications · 17:1138· Co-first author· IF 14.7

Ultra-broadband near- to mid-infrared electro-optic modulator on thin-film lithium niobate

Q. Li*, Q. Yi*, A. Sun*, A. Pan*, et al. (* equal contribution)
HUST · Fudan University · CAS Semiconductor Institute

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TL;DR A thin-film lithium niobate (TFLN) electro-optic modulator with an unprecedented 800 nm operational bandwidth — covering the full O-to-U telecom bands and extending into the 2-µm regime. It shows >67 GHz EO bandwidth across O/S/C/L bands (~100 GHz at the centre bands) and >50 GHz at 2 µm, enabling single-lane >240 Gbps PAM-4 in the O-U range and a record 170 Gbps PAM-4 at 2 µm.

TFLN near- to mid-IR electro-optic modulator

Background

Conventional near-infrared telecom bands are running into capacity limits, motivating wide-band optical-communication systems that span from near-IR all the way into the mid-IR. This demands core optical components combining broadband bandwidth with high-speed operation, but existing modulators struggle to maintain wide operational bandwidth because of waveguide dispersion and velocity mismatch between the optical and electrical waves.

Device & Performance

We demonstrate a thin-film lithium niobate (TFLN) EO modulator with an 800 nm operational bandwidth, covering the full O-to-U telecom range and extending into the 2 µm waveband. Its EO 3-dB bandwidth exceeds 67 GHz across the O/S/C/L bands (~100 GHz at the centre bands) and exceeds 50 GHz at 2 µm.

Highlights

800 nm operational bandwidth — covering O–U telecom bands and extending into 2 µm
>67 GHz EO bandwidth across O/S/C/L (~100 GHz at centre bands); >50 GHz at 2 µm
Single-lane >240 Gbps PAM-4 across O-U bands; record 170 Gbps PAM-4 at 2 µm
Establishes TFLN as a multispectral photonics platform — bridging telecom and emerging 2 µm technologies

Citation

Q. Li*, Q. Yi*, A. Sun*, A. Pan* et al., "Ultra-broadband near- to mid-infrared electro-optic modulator on thin-film lithium niobate," Nature Communications, 17:1138, 2026.