Grating coupler integrated photodiodes for plasmon resonance based sensing
Grating coupler integrated photodiodes for plasmon resonance based sensing
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DOI：
10.1039/c0lc00081g
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发表时间：
2011-01-01
期刊：
影响因子：
6.1
通讯作者：
Dana, Aykutlu
中科院分区：
文献类型：
--
作者：
Turker, Burak;Guner, Hasan;Dana, Aykutlu
在这项工作中，我们展示了一种集成传感器，它结合了一个光栅耦合的等离子体共振面和一个平面光电二极管。等离子体增强透射率被用作敏感的折射率(RI)传感机制。通过集成光电二极管调节准直光束在尖锐等离子体共振条件下的入射角，来监测增强的光透射率。有效折射率(RI)的微小变化会移动共振角，从而导致光电流的变化。由于平面传感机构，该设计允许高面积密度的传感光点。在设计中，没有促进光的共振传输的孔，使得制造过程易于实施，并且对制造错误相对不敏感。理论和实验结果吻合较好。使用8 mW He-Ne激光获得了6.3×10(-6)RIU/根赫兹的等效长期RI噪声，而散粒噪声的理论灵敏度为5.61×10(-9)RIU/根赫兹。该器件充分利用了光栅耦合等离子体共振的优点，例如提高了对非零方位角入射的灵敏度。讨论了平衡检测和最佳等离子体耦合条件对灵敏度的进一步提高。
In this work, we demonstrate an integrated sensor combining a grating-coupled plasmon resonance surface with a planar photodiode. Plasmon enhanced transmission is employed as a sensitive refractive index (RI) sensing mechanism. Enhanced transmission of light is monitored via the integrated photodiode by tuning the angle of incidence of a collimated beam near the sharp plasmon resonance condition. Slight changes of the effective refractive index (RI) shift the resonance angle, resulting in a change in the photocurrent. Owing to the planar sensing mechanism, the design permits a high areal density of sensing spots. In the design, absence of holes that facilitate resonant transmission of light, allows an easy-to-implement fabrication procedure and relative insensitivity to fabrication errors. Theoretical and experimental results agree well. An equivalent long-term RI noise of 6.3 x 10(-6) RIU/root Hz is obtained by using an 8 mW He-Ne laser, compared to a shot-noise limited theoretical sensitivity of 5.61 x 10(-9) RIU/root Hz. The device features full benefits of grating-coupled plasmon resonance, such as enhancement of sensitivity for non-zero azimuthal angle of incidence. Further sensitivity enhancement using balanced detection and optimal plasmon coupling conditions are discussed.