Highly Sensitive 1 × 8 Parallel Multiplexing of Ultra-Compact Integrated 1D Photonic Crystal Sensor Array Based on Silicon-on-Insulator Platform

We design a 1 x 8 highly sensitive ultra-compact on-chip integrated sensor array consisting of a 1 x 8 power splitter, eight one-dimensional photonic crystal slot nanobeam cavities (1DPC-SNCs) connected by additional 1D photonic crystal tapered nanobeam bandgap filters (1DPC-TNBF), and an 8 x 1 power combiner. The performance of the device is numerically demonstrated by three-dimensional finite difference-time-domain (3D-FDTD) method. The whole structure is lying on top of a 2 μm buried silicon oxide layer, while remaining high sensitivities (over 400 nm/RIU) of the eight sensors, simultaneously. The proposed 1DPC-SNCs can reach a high-quality factor of 3.6 x 10 ⁵ . On account of the additional band-stop filters and the 8 x 1 power combiner, eight sensing segments interrogated simultaneously by one input and one output port is realized, with the ultra-compact footprint of 64x16 μm ² (26x16 μm ² in sensing region). Therefore, this design is a promising platform for realizing large-scale photonic integrated circuits with high integration density, especially for ultra-compact multiple on-chip sensing.