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High-Sensitivity Polarization-Independent Biochemical Sensor Based on Silicon-on-Insulator Cross-Slot Waveguide

Pan, C. & Rahman, B. M. (2016). High-Sensitivity Polarization-Independent Biochemical Sensor Based on Silicon-on-Insulator Cross-Slot Waveguide. IEEE Journal of Selected Topics in Quantum Electronics, 23(2), pp. 64-71. doi: 10.1109/jstqe.2016.2594094


Slot waveguides reported so far are strongly polarization dependent. The concept of a novel cross-slot waveguide (WG) is presented here, which contains both vertical and horizontal slots and supports the power enhancement in the slot region for both the quasi-TE and quasi-TM polarizations. This WG can be fabricated by exploiting well developed CMOS technology. For the unpolarized operating light, the cross-slot WG is optimized to have the maximum total slot confinement factors for the two polarizations. As for a polarization-independent design, confinement in slot for each polarization can reach 39.4% when the silicon core width and height are set to around 223 and 216 nm, respectively. It is shown here that a biochemical sensor employing a cross-slot-WG exhibits a significantly better sensitivity, compared to either a vertical-slot-WG or a horizontal-slot-WG-based biochemical sensor. As an example, when both the vertical slot width and horizontal slot height are set to 100 nm, its sensitivity is almost double compared with a simple vertical or horizontal slot with 100 nm gap.

Publication Type: Article
Additional Information: © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.
Publisher Keywords: silicon photonics, Biochemical sensing, cross-slot waveguide, finite element analysis, high sensitivity, polarization independent, Silicon, Indexes, Sensitivity, Optical sensors, Biosensors, Biomedical optical imaging
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
Departments: School of Science & Technology > Engineering
SWORD Depositor:
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