Chemical–mechanical surface treatment method for high-quality crystalline whispering gallery mode microresonators
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2022-11-01 |
| Journal | Journal of Optical Technology |
| Authors | K. N. Min’kov, A. N. Danilin, Artem E. Shitikov, I. K. Gorelov, M. L. Galkin |
| Institutions | National Research University Higher School of Economics, Skolkovo Institute of Science and Technology |
| Citations | 1 |
Abstract
Section titled “Abstract”Subject of study. A novel method for the surface treatment of high-quality crystalline optical microresonators with whispering gallery modes (WGMs) based on chemical-mechanical polishing using magnesium fluoride microresonators is proposed. The proposed method can be applied to brittle and soft materials. Aim of study. The study aimed to develop a new effective method for the surface treatment of crystalline WGM microresonators based on asymptotic chemical-mechanical polishing. Methods. Magnesium fluoride resonators fabricated by diamond turning were polished using the chemical-mechanical polishing process. The values of the quality factor (Q-factor) and roughness were measured using independent methods to determine the numerical relationship between them: roughness was measured using an interference microscope, and the Q-factor was determined based on the half-width of the resonant power dip at critical coupling. The focus was on the investigation of the properties of the polished suspension: the size distribution of the suspended particles was determined before polishing using the dynamic light scattering method and a scanning electron microscope. Main results. A novel surface treatment method for high-quality crystalline optical WGM microresonators that reduces the polishing time by at least three times has been developed and successfully applied. The proposed method ensures the fabrication of resonators with a small radius and a Q-factor of at least 1×109 and helps maintain their shapes. The surface roughness along the resonator generatrix after chemical-mechanical polishing was ∼5nm, which corresponds to 1-1.5 unit cells of the crystal. Practical significance. The chemical-mechanical polishing method helps reduce the polishing time and improve the surface quality of complex structures. In addition, it can facilitate the automation of the microresonator fabrication process.