报告题目：Novel whispering gallery mode micro resonators and their applications（新型回音壁模式光学微腔及其应用）
报 告 人：Yong Yang 杨勇 (日本冲绳科学技术研究所)
报告时间：2017年 5 月 27 日（周六）10:00
报告地点：校本部G401
邀请人：陈玺
报告摘要：
Whispering gallery mode resonators (WGRs) featuring ultrahigh quality factors and relatively small mode volume, have many potential applications in the modern photonics and fundamental physics researches. WGRs are widely used in areas such as cavity QED, ultrahigh sensitive sensing, nonlinear optics and optomechanics.
In this presentation, I am going to introduce recently developed new types of WGRs named micropendulum, microbubble and microbottle and discuss about the experimental progresses in utilizing the novel WGRs in areas such as sensing, trapping and frequency comb generations.
1. When a microsphere is connected to a pivot with a flexible stem, it forms a cantilever structure which swings like a pendulum due to the Brownian motion of the object. Here we detected the pendulum motion using an evanescently coupled tapered fiber to a high Q WGM. Furthermore, such system is a dissipative optomechanical system with the dispersion coexisting, which was proved from the measured asymmetric noise spectrum. By combining the micropendulum with the microbubble, a photonic molecule was generated. Trapping in such system will be discussed.
2. Microbubble is a hollow WGR where the properties of the microbubble can be modified by injecting different materials in the inner core. This can be used as a candidate for sensing. In the presentation, many physical sensing e.g. temperature, pressure in microbubbles will be reported. When the microbubble is in the so called quasi-droplet regime, the sensitivity will be highly boosted. By functionalizing the surface of the microbubble, tunable microlaser can also be achieved.
3. In recent years, frequency comb generation in whispering galley mode resonators (WGR) has shown potential in both fundamental and practical areas of research. In WGRs, it is important to control the dispersion for the four-wave mixing process to occur. I have found two different ways to control the dispersion with the microbottle and microbubble. With these novel WGRs, I have successfully realized widely spanned, dispersion managed frequency comb in the IR range and a direct generation of visible comb for the first time.
