Department of Biosystems Engineering, Chungbuk National University, Cheongju 361-763, Korea.
Sensors (Basel). 2012 Oct 22;12(10):14144-57. doi: 10.3390/s121014144.
The opto-fluidic ring resonator (OFRR) biosensor is numerically characterized in whispering gallery mode (WGM). The ring resonator includes a ring, a waveguide and a gap separating the ring and the waveguide. Dependence of the resonance characteristics on the resonator size parameters such as the ring diameter, the ring thickness, the waveguide width, and the gap width between the ring and the waveguide are investigated. For this purpose, we use the finite element method with COMSOL Multiphysics software to solve the Maxwell's equations. The resonance frequencies, the free spectral ranges (FSR), the full width at half-maximum (FWHM), finesse (F), and quality factor of the resonances (Q) are examined. The resonant frequencies are dominantly affected by the resonator diameter while the gap width, the ring thickness and the waveguide width have negligible effects on the resonant frequencies. FWHM, the quality factor Q and the finesse F are most strongly affected by the gap width and moderately influenced by the ring diameter, the waveguide width and the ring thickness. In addition, our simulation demonstrates that there is an optimum range of the waveguide width for a given ring resonator and this value is between ~2.25 μm and ~2.75 μm in our case.
光流体环形谐振器（OFRR）生物传感器在 whispering gallery 模式（WGM）下进行数值特性分析。环形谐振器包括一个环形、一个波导以及一个将环形和波导隔开的间隙。研究了谐振器尺寸参数（如环形直径、环形厚度、波导宽度和环形与波导之间的间隙宽度）对谐振特性的影响。为此，我们使用 COMSOL Multiphysics 软件中的有限元方法来求解麦克斯韦方程组。研究了谐振频率、自由光谱范围（FSR）、半最大值全宽（FWHM）、精细度（F）和谐振的品质因数（Q）。谐振频率主要受谐振器直径的影响，而间隙宽度、环形厚度和波导宽度对谐振频率的影响可以忽略不计。FWHM、品质因数 Q 和精细度 F 受间隙宽度的影响最大，受环形直径、波导宽度和环形厚度的影响次之。此外，我们的模拟表明，对于给定的环形谐振器，存在一个最佳的波导宽度范围，在我们的情况下，这个值在 2.25μm 到 2.75μm 之间。
