Numerical characterization of whispering-gallery mode optical microcavities
Numerical characterization of whispering-gallery mode optical microcavities
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DOI：
10.1364/ao.45.000611
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发表时间：
2006-02-01
期刊：
影响因子：
1.9
通讯作者：
Pau, S
中科院分区：
文献类型：
--
作者：
Guo, ZX;Quan, HY;Pau, S
我们描述了回音廊模式光学共振中的平面微腔。微腔由波导和微盘组成，波导和微盘之间有一个纳米级的间隙。这种器件可以用传统的微电子技术在硅基薄膜上制作。为了表征这些类型的腔，我们研究了范围广泛的谐振器配置参数，包括微盘的大小、间隙的宽度和波导的尺寸。用有限元方法求解麦克斯韦方程。得到了开谐振态和非共振态下的电场和能量密度分布，并进行了比较。在一次共振作用下，微盘内部形成了一个具有较强电场和较高能量密度的亮环。而在二阶共振下，有两个明亮的环，且内环的光强强于外环。共振频率及其自由光谱范围主要由微盘的大小决定。间隙对共振频率的影响是可以观察到的，尽管它是微小的。带隙对谐振的半高全宽(FWHM)、精细度和品质因数有很大影响。当间隙宽度从100 nm增加到300 nm时，Q值和FINESSE显著增加，而半高宽减小。波导宽度对Q值、半高宽和纤度也有明显的影响。(C)2006年美国光学学会。
We characterize planar microcavities in whispering-gallery mode optical resonances. The microcavity consists of a waveguide and a microdisk, and a nanoscale gap separates the waveguide and the microdisk. The devices can be fabricated on Si-based thin films by using conventional microelectronics techniques. To characterize these types of cavity, we study a broad range of resonator configuration parameters including the size of the microdisk, the width of the gap, and the waveguide dimensions. The finite-element method is used for solving Maxwell's equations. The electric fields and the energy density distributions are obtained and compared between the on-resonance and off-resonance situations. A brilliant ring with a strong electric field and a high-energy density is found inside the periphery of the microdisk under first-order resonance. While under second-order resonance, there are two bright rings, and the light intensity in the inner ring is stronger than that in the outer ring. The resonant frequencies and their free spectral ranges are predominantly determined by the size of the microdisk. The gap effect on the resonant frequencies is observable, although it is minor. The gap strongly affects the full width at half-maximum (FWHM), finesse, and quality factor of the resonances. With an increase in the gap width from 100 to 300 nm, both the Q value and finesse increase substantially, while the FWHM decreases. The waveguide width has a visible influence on the Q value, FWHM, and finesse as well. (c) 2006 Optical Society of America.