Optical biosensors on silicon platforms have demonstrated their great potential in label-free detection and analysis tool. The major challenge of ring resonator based optical biosensors is their high sensitivity to temperature variations. We have designed a double-ring resonator biosensor using a vertical coupling method. Simulation results show that the double-ring configuration effectively eliminates the temperature and environmental fluctuations by the resonant wavelength shift correction induced from the reference ring. The coupling gap in the vertical coupling method can be tuned by timing the deposition/growth rate of the space layer, without the need of any advanced lithography. The vertical coupling method allows a low fabrication cost.

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Silicon Photonics VII
Department of Electronics

Xiong, Y. (Yule), & Ye, W.N. (2012). Temperature-independent vertically coupled double-ring sensor. In Proceedings of SPIE - The International Society for Optical Engineering. doi:10.1117/12.908902