TY - JOUR
T1 - Thin-Film Lithium Niobate Based Acousto-Optic Modulation Working at Higher-Order TE1 Mode
AU - Yang, Yang
AU - Xu, Yin
AU - Huang, Dongmei
AU - Li, Feng
AU - Dong, Yue
AU - Zhang, Bo
AU - Ni, Yi
AU - Wai, Alex
N1 - Funding Information:
Funding: This research was funded by the National Key R&D Program of China, grant number 2019YFB1803904, Research Grant Council of Hong Kong SAR, grant number PolyU152241/18E, Natural Science Foundation of Jiangsu Province, grant number BK20200592, and Fundamental Research Founds for the Central Universities, grant number JUSRP12024.
Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2022/1
Y1 - 2022/1
N2 - 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 × 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 (Vπ L) 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., Vπ L > 0.04 V·cm for AOM, Vπ L > 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.
AB - 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 × 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 (Vπ L) 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., Vπ L > 0.04 V·cm for AOM, Vπ L > 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.
KW - Acousto-optic modulation
KW - Thin-film lithium niobate
KW - Photonic integrated components
UR - http://www.scopus.com/inward/record.url?scp=85122239631&partnerID=8YFLogxK
U2 - 10.3390/photonics9010012
DO - 10.3390/photonics9010012
M3 - Journal article
AN - SCOPUS:85122239631
SN - 2304-6732
VL - 9
JO - Photonics
JF - Photonics
IS - 1
M1 - 12
ER -