利用双面金属包覆波导中的超高阶导模对导波层折射率极其敏感的特性,提出一种新型的生物传感器。与传统的表面等离子共振、泄漏波导以及反对称波导等消逝场生物传感器相比,该传感器的待测样品放置在导波振荡场中,样品折射率的微小变化都将引起输出光强的极大改变,从而极大提高了传感器的灵敏度和分辨率。初步的实验结果显示在现有噪声水平下至少能够分辨1ppm的葡萄糖溶度改变。预计该传感器将在环境监测、食品安全、生物医学和疾病诊断等领域有着极其广泛的应用前景和巨大的市场潜力。
A novel oscillating field biosensor was proposed utilizing ultrahigh-order modes excitated in a symmetrical metal cladding waveguide(SMCW).Different from the conventional biosensors,such as surface plasmon resonance sensor(SPRS),leaky mode waveguide sensor(LWS) and reverse symmetry waveguide sensor(RSWS),the sample is placed inside the guiding layer.Since the guiding layer supports a high intensity oscillating field,the intensity of output light is rather sensitive to the tiny variation of refractive index,which leads to very high sensitivity and resolution.Based on the noise level,1ppm variation of the glucose solution was detected in the experiment.The proposed scheme is expected to have a wide application and promising future in various biomedical detections.