Ultracompact On-Chip Multiplexed Sensor Array Based on Dense Integration of Flexible 1-D Photonic Crystal Nanobeam Cavity With Large Free Spectral Range and High Q-Factor

IEEE Photonics Journal

Chuan Wang¹  Daquan Yang²  Bo Wang²  Yuefeng Ji²  Xin Chen² 

[1] State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, China;State Key Laboratory of Information Photonics and Optical Communications, School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing, China;

关键词: Optical interconnects;    Photonic crystals;    Nanocavities;    Sensors;    Silicon nanophotonics;    Integrated nanophotonic systems;   

DOI  :  10.1109/JPHOT.2017.2710136

来源: DOAJ

【 摘 要 】

A method for the dense integration of one-dimensional (1-D) photonic crystal nanobeam cavity (PCNC) based integrated sensor array (1-D-PCNC-ISA) is proposed. The 1-D-PCNC-ISA consists of multiple parallel-connected sensing channels with airgap separations. On each channel, only a single flexible 1-D-PCNC sensor with large free spectral range (FSR) and high Q-factor is contained. With proper engineering of the FSR, multiple ultracompact high-sensitivity 1-D-PCNC sensors can be integrated into microarrays without resonance overlap, and be interrogated simultaneously between a single input/output ports. Using 3-D finite-difference-time-domain (3-D-FDTD) method, the performance of the device is investigated theoretically in the whole paper. With optimization design, a large FSR as wide as 197 nm and high Q-factor 2 x 10⁵ can be achieved. Moreover, the refractive index sensitivities of a 5-channel 1-D-PCNC-ISA as high as 170.6, 152.7, 138.5, 128.1, and 120.5 nm/RIU are obtained. Particularly, the footprint of a 5-channel 1-D-PCNC-ISA is ~7μm x 65μm (width by length), which is decreased by three orders of magnitude compared to the sensor arrays based on 2-D-PC cavity platforms. To the best of our knowledge, this is for the first time that a 1-D-PCNC based multichannel parallel-connected sensor array has been displayed with channel spacing as small as 0.195μm, extinction ratio > 20 dB and Q-factor > 10⁵, respectively, without using particular materials or complexities in fabrication. Both the specific result and the general idea are promising in future ultracompact lab-on-a-chip applications and nanophotonic integrations.

【 授权许可】

Unknown