Improving the detection limit for on-chip photonic sensors based on subwavelength grating racetrack resonators
Improving the detection limit for on-chip photonic sensors based on subwavelength grating racetrack resonators
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DOI：
10.1364/oe.25.010527
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发表时间：
2017-05-01
期刊：
影响因子：
3.8
通讯作者：
Chen, Ray T.
中科院分区：
文献类型：
--
作者：
Huang, Lijun;Yan, Hai;Chen, Ray T.
与传统的条形波导微腔相比，亚波长光栅波导微腔由于增强了光子与分析物的相互作用，具有更高的灵敏度和更低的检测限。由于传感器，特别是生物传感器，通常用于吸收性的周围环境中，这是非常具有挑战性的进一步提高检测限的SWG环形谐振器通过简单地增加灵敏度。由于模式与分析物重叠较大而导致的高灵敏度也带来了显著的吸收损耗，这恶化了谐振器的品质因数。为了探索SWG环形谐振器的潜力，我们从理论和实验上优化了超灵敏的横磁模式SWG跑道谐振器，以获得最大的品质因数，从而最低的检测限。在1550 nm附近的品质因数为9800，在水环境中的灵敏度为429.7 ± 0.4nm/RIU。它对应于3.71 × 10（-4）RIU的检测限（λ/S.Q），这标志着与SWG微量元素传感器报告的最佳值相比降低了32.5%。(C)2017美国光学学会
Compared to the conventional strip waveguide microring resonators, subwavelength grating (SWG) waveguide microring resonators have better sensitivity and lower detection limit due to the enhanced photon-analyte interaction. As sensors, especially biosensors, are usually used in absorptive ambient environment, it is very challenging to further improve the detection limit of the SWG ring resonator by simply increasing the sensitivity. The high sensitivity resulted from larger mode-analyte overlap also brings significant absorption loss, which deteriorates the quality factor of the resonator. To explore the potential of the SWG ring resonator, we theoretically and experimentally optimize an ultrasensitive transverse magnetic mode SWG racetrack resonator to obtain maximum quality factor and thus lowest detection limit. A quality factor of 9800 around 1550 nm and sensitivity of 429.7 +/- 0.4nm/RIU in water environment are achieved. It corresponds to a detection limit (lambda/S.Q) of 3.71 x 10(-4) RIU, which marks a reduction of 32.5% compared to the best value reported for SWG microring sensors. (C) 2017 Optical Society of America