Simulation and Analysis of Single-Mode Microring Resonators in Lithium Niobate Thin Films

Huangpu Han,Bingxi Xiang,Jiali Zhang

doi:10.3390/cryst8090342

Abstract

The single-mode microring resonators on lithium niobate thin films were designed and simulated using 2.5-D variational finite difference time domain mode simulations from Lumerical mode Solutions. The single-mode conditions and the propagation losses of lithium niobate planar waveguide with different SiO2 cladding layer thicknesses were studied and compared systematically. The optimization of design parameters such as radii of microrings and gap sizes between channel and ring waveguides were determined. The key issues affecting the resonator design such as free spectral range and Quality Factor were discussed. The microring resonators had radius R = 20 μm, and their transmission spectrum had been tuned using the electro-optical effect.

Highlights

Lithium niobate (LiNO3, LN) is one of the most promising materials because of its excellent electro-optical, piezoelectric, pyroelectric, photo-elastic and non-linear properties [1]
The microring resonators have been designed on various types of materials such as silicon [8], germanium-doped silica-on-silicon [9], polymers [10], lithium niobate [11,12,13] and so forth
We presented results from finite difference time domain domain (FDTD)

Summary

Introduction

Lithium niobate (LiNO3 , LN) is one of the most promising materials because of its excellent electro-optical, piezoelectric, pyroelectric, photo-elastic and non-linear properties [1]. The microring resonator is one of the important elements in integrated photonic systems. Key optical design parameters of laterally coupled LNOI‐based microring resonators resonators were characterized using using2.5‐D. full-vectorial finite difference method were performed by varying the geometrical parameters vectorial finite difference method were performed by varying the geometrical parameters of of waveguide to investigate and the waveguide configurations configurations to investigate the the single-mode single‐mode conditions conditions and the propagation propagation losses losses of of LN cladding layer layer thicknesses. As a very important element radii and gap sizes These parameters affected FSR and Q‐factor directly.

Device Description

Discussion

Effective

Effective index of the TE

Conclusions