{"title":"Double-slot micro-ring resonators with trapezoidal subwavelength grating as ultra-sensitive biochemical sensors","authors":"","doi":"10.1016/j.optcom.2024.131256","DOIUrl":null,"url":null,"abstract":"<div><div>Silicon-based refractive index sensors are of significance in the detection of gases, biological substances and chemical compounds. Among these, optical microcavities can confine the optical field to the micrometre-scale region, and possess the advantages of high <em>Q</em> factor, small size and easy integration. In this paper, a trapezoidal subwavelength grating (SWG) is introduced into a slot micro-ring resonator, and the mode splitting is employed to enrich the supported standing wave modes and optimize the spatial profiles of the resonant modes. The modes’ <em>Q</em> factor is improved and the high sensitivity and low detection limit is achieved. The optimal trapezoidal subwavelength grating double slot micro-ring resonator (T-SWGDSMRR) structure is obtained by designing the structural parameters and analyzing their effects on the sensing performance parameters and spectral characteristics. The T-SWGDSMRR, designed for detecting the glucose solution, demonstrated a low detection limit of <span><math><mrow><mn>3.3</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span> RIU and an ultra-high <em>Q</em> factor of up to 100825, accompanied by a refractive index sensitivity of 424 nm/RIU. Finally, a cascaded double micro-ring sensor is proposed using the vernier effect, through cascading the T-SWGDSMRR with a referential ring, the sensitivity is enhanced to 12828 nm/RIU, and the limit of detection is <span><math><mrow><mn>3.12</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup></mrow></math></span> RIU.</div></div>","PeriodicalId":19586,"journal":{"name":"Optics Communications","volume":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Optics Communications","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0030401824009933","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"OPTICS","Score":null,"Total":0}
引用次数: 0
Abstract
Silicon-based refractive index sensors are of significance in the detection of gases, biological substances and chemical compounds. Among these, optical microcavities can confine the optical field to the micrometre-scale region, and possess the advantages of high Q factor, small size and easy integration. In this paper, a trapezoidal subwavelength grating (SWG) is introduced into a slot micro-ring resonator, and the mode splitting is employed to enrich the supported standing wave modes and optimize the spatial profiles of the resonant modes. The modes’ Q factor is improved and the high sensitivity and low detection limit is achieved. The optimal trapezoidal subwavelength grating double slot micro-ring resonator (T-SWGDSMRR) structure is obtained by designing the structural parameters and analyzing their effects on the sensing performance parameters and spectral characteristics. The T-SWGDSMRR, designed for detecting the glucose solution, demonstrated a low detection limit of RIU and an ultra-high Q factor of up to 100825, accompanied by a refractive index sensitivity of 424 nm/RIU. Finally, a cascaded double micro-ring sensor is proposed using the vernier effect, through cascading the T-SWGDSMRR with a referential ring, the sensitivity is enhanced to 12828 nm/RIU, and the limit of detection is RIU.
期刊介绍:
Optics Communications invites original and timely contributions containing new results in various fields of optics and photonics. The journal considers theoretical and experimental research in areas ranging from the fundamental properties of light to technological applications. Topics covered include classical and quantum optics, optical physics and light-matter interactions, lasers, imaging, guided-wave optics and optical information processing. Manuscripts should offer clear evidence of novelty and significance. Papers concentrating on mathematical and computational issues, with limited connection to optics, are not suitable for publication in the Journal. Similarly, small technical advances, or papers concerned only with engineering applications or issues of materials science fall outside the journal scope.