|Y. Liang, Q. Liu, Z. Wu, G. Morthier, M. Zhao
|Cascaded microrings biosensor fabricated on polymer platform
|12 (Dimensions.ai - last update: 3/3/2024)
2 (OpenCitations - last update: 19/4/2024)
Look up on Google Scholar
We have previously demonstrated single microring biosensors with good performance on the polymer platform. However, polymer waveguides have a small refractive index contrast which leads to a large roundtrip length for the microring. As a result, polymer-based microring biosensors usually have a small free spectral range (FSR) which is inversely proportional to the roundtrip length and hampers the tracing of the spectrum shifting in the measurement. A cascade of two microring resonators based on the Vernier effect is applied in this article in order to improve the FSR. The optical polymer material, Ormocore, which has a large transparent window, is used in the fabrication. The biosensor is fabricated using an UV-based soft imprint technique which is considered as cost-effective and suitable for mass-production. By optimizing the volume ratio of Ormocore and the thinner maT, the device can be fabricated almost without residual layer. A two-step fitting method, including the single peak fitting and the whole envelope fitting is applied in order to trace the spectral shift accurately. Finally, the biosensor is characterized and the FSR is obtained as 4.6 nm which is 16 times that of the single microring biosensor demonstrated in our previous work. Moreover, the sensitivity can also be magnified by 16 times thanks to the Vernier effect.
Related Research Topics