Open AccessHigh-performance racetrack resonator in silicon nitride - thin film lithium niobate hybrid platform
Author(s) -
Abu Naim R. Ahmed,
Shouyuan Shi,
Andrew Mercante,
Dennis W. Prather
Publication year - 2019
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.030741
Subject(s) - lithium niobate , materials science , resonator , optics , free spectral range , optoelectronics , modulation (music) , optical modulator , electrode , silicon nitride , electro optic modulator , energy conversion efficiency , thin film , silicon , phase modulation , physics , nanotechnology , quantum mechanics , acoustics , phase noise
In this paper, we propose an electro-optic modulator design in a hybrid Si 3 N 4 -X-cut LiNbO 3 . The modulator is based on a modified racetrack resonator and performs at both DC and heightened frequencies. Here the driving electrodes are defined along the straight section of the racetrack. This is done to maximize modulation and minimize modulation-cancelation that occurs in a conventional X-cut LiNbO 3 -based resonator due to the directional change of the electric field in the micro-ring. The single bus racetrack resonator is formed in a hybrid Si 3 N 4 -LiNbO 3 platform, to guide the optical mode. The fabricated device is characterized and has a measured tunability and intrinsic quality factor (Q) of 2.9 pm/V and 1.3 × 10 5 , respectively. In addition, the proposed racetrack device exhibits enhanced electro-optic conversion efficiency at modulation frequencies that match with the racetrack's optical free spectral range (FSR). For example, at the modulation frequency of 25 GHz, which corresponds to the fabricated device's optical FSR frequency, a ∼10 dB increase in electro-optic conversion efficiency is demonstrated. With the enhancement, our measured device demonstrates a conversion efficiency comparable to non-resonant thin-film LiNbO 3 devices that possess RF electrodes that are 10 times longer in length.