Influence of the Surface Roughness of a Silicon Disk Resonator on Its Q-Factor

Anastasia V Yakuhina,Sergey S Generalov,Alexey S Kadochkin,Vladimir V Amelichev,Vyacheslav V Svetukhin,Dmitry V Gorelov

doi:10.3390/photonics8060225

Anastasia V Yakuhina, Sergey S Generalov + Show 4 more

Open Access

https://doi.org/10.3390/photonics8060225

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Abstract

This article presents a silicon disk resonator of the whispering-gallery-mode (WGM) type. The calculated Q-factor of the silicon WGM resonator was 107. Two methods of studying the surface roughness of a silicon WGM resonator with a nonlinear profile by means of Helios 650 scanning electron microscope and Bruker atomic force microscope (AFM) are presented. The results obtained by the two methods agreed well with each other. A comparison of the surface roughness values of WGM resonators manufactured using different technological approaches is presented. Based on the obtained data, a preliminary estimated Q-factor calculation of the resonators was performed, which was refined by numerical calculation using the finite-difference time-domain (FDTD) method. The effect of the surface roughness of the resonator on its Q-factor was found. Reducing the surface roughness of the resonator from 30 nm to 1–2 nm led to an increase in its Q-factor from 104 to 107.

Highlights

Research in the field of developing devices that use photons as the main carrier of information is gaining more and more relevance
The reason is that such waveguide structures have a high Q-factor and relatively low optical losses in combination with a small volume of the mode [1]
It is possible to build optical filters using WGM resonators [2], narrow-band lasers with external resonant feedback [3,4], tunable delay lines [5,6] used for buffering signals, optical or radio frequency (RF) phase arrays [7], sensors [8,9], the creation of micro-optoelectromechanical gyroscopic systems [10] and other applications in the field of integrated photonics [11]

Summary

Introduction

Research in the field of developing devices that use photons as the main carrier of information is gaining more and more relevance. The research and wide application of WGM waveguides and resonators directly depends on how accessible and reproducible their manufacturing technology will be.

Results

Conclusion