National Electronics and Computer Technology Center, National Science and Technology Development Agency, Thailand Science Park, Pathumthani, Thailand.
Opt Lett. 2011 Sep 1;36(17):3524-6. doi: 10.1364/OL.36.003524.
A novel on-axis one-element polarization-independent light in- and out-coupling mechanism for surface plasmon resonance (SPR) is proposed. The system utilizes an integrated high-NA concentric chirped grating to both focus the incident light on the metallic film and collimate the reflected beam onto a CCD array to extract the SPR signal. With NA up to 1.47, a broad sensing dynamic range from n=1 to 1.35 can be achieved. An analytical model is implemented to demonstrate the dependency of the radial location of the resonances on the detecting substance and its sensitivity to the change of the refractive index. The model shows a trend similar to rigorous ray-tracing calculations.
提出了一种用于表面等离子体共振（SPR）的新颖的轴上单元件偏振无关的光输入和输出耦合机制。该系统利用集成的高数值孔径同心啁啾光栅来聚焦入射光在金属膜上，并准直反射光束到 CCD 阵列上，以提取 SPR 信号。通过达到 NA 高达 1.47，可以实现从 n=1 到 1.35 的宽传感动态范围。实现了一个分析模型来演示共振的径向位置对检测物质的依赖性及其对折射率变化的灵敏度。该模型显示出与严格光线追踪计算相似的趋势。
