Thin-Film Lithium Niobate Based Acousto-Optic Modulation Working at Higher-Order TE1 Mode

Photonics

卷:9

Yue Dong¹  Yang Yang¹  Yin Xu¹  Bo Zhang¹  Yi Ni¹  Dongmei Huang²  P. K. A. Wai³  Feng Li³ 

[1] Department of Electronic Engineering, School of IoT Engineering, Jiangnan University, Wuxi 214122, China;

[2] Photonics Research Center, Department of Electrical Engineering, The Hong Kong Polytechnic University, Hong Kong, China;

[3] The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, China;

关键词: acousto-optic modulation;    thin-film lithium niobate;    photonic integrated components;   

DOI  :  10.3390/photonics9010012

来源: DOAJ

【 摘 要 】

Acousto-optic modulation (AOM) is regarded as an effective way to link multi-physical fields on-chip. We propose an on-chip AOM scheme based on the thin-film lithium niobate (TFLN) platform working at the higher-order TE₁ mode, rather than the commonly used fundamental TE₀ mode. Multi-physical field coupling analyses were carried out to obtain the refractive index change of the optical waveguide (>$6.5\times {10}^{-10}$ for a single phonon) induced by the enhanced acousto-optic interaction between the acoustic resonator mode and the multimode optical waveguide. By using a Mach-Zehnder interferometer (MZI) structure, the refractive index change is utilized to modulate the output spectrum of the MZI, thus achieving the AOM function. In the proposed AOM scheme, efficient mode conversion between the TE₀ and TE₁ mode is required in order to ensure that the AOM works at the higher-order TE₁ mode in the MZI structure. Our results show that the half-wave-voltage-length product (V_πL) is <0.01 V·cm, which is lower than that in some previous reports on AOM and electro-optic modulation (EOM) working at the fundamental TE₀ mode (e.g., V_πL > 0.04 V·cm for AOM, V_πL > 1 V·cm for EOM). Finally, the proposed AOM has lower loss when compared with EOM because the electrode of the AOM can be placed far from the optical waveguide.

【 授权许可】

Unknown