Waveguide-Integrated Two-Dimensional Material Photodetectors in Thin-Film Lithium Niobate

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Original languageEnglish
Article number2300045
Number of pages8
Journal / PublicationAdvanced Photonics Research
Issue number7
Online published20 Apr 2023
Publication statusPublished - Jul 2023



Thin-film lithium niobate on insulator (LNOI) is a promising platform for optical communications, microwave photonics, and quantum technologies. While many high-performance devices like electro-optic modulators and frequency comb sources have been achieved on LNOI platform, it remains challenging to realize photodetectors (PDs) on LNOI platform using simple and low-cost fabrication techniques. 2D materials are excellent candidates to achieve photodetection since they feature strong light-matter interaction, excellent mechanical flexibility, and potential large-scale complementary metal–oxide–semiconductor-compatible fabrication. Herein, this demand is addressed using an LNOI-2D material platform, and two types of high-performance LNOI waveguide-integrated 2D material PDs, namely graphene and tellurium (Te), are addressed. Specifically, the LNOI-graphene PDs feature broadband operations at telecom and visible wavelengths, high normalized photocurrent-to-dark current ratios up to 3 × 106  W−1, and large 3-dB photoelectric bandwidths of ≈40 GHz, simultaneously. The LNOI-Te PDs on the other hand provide ultrahigh responsivities of 7 A  W−1 under 0.5 V bias for telecom signals while supporting GHz frequency responses. The results show that the versatile properties of 2D materials and their excellent compatibility with LNOI waveguides could provide important low-cost solutions for system operating point monitoring and high-speed photoelectric conversion in future LNOI photonic integrated circuits. © 2023 The Authors. Advanced Photonics Research published by Wiley-VCH GmbH

Research Area(s)

  • 2D materials, graphene, photodetector, tellurium, thin-film lithium niobate

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