文章基本信息

标题：Diffractive Optical Analysis for Refractive Index Sensing using Transparent Phase Gratings
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作者：Nityanand Kumawat ; Parama Pal ; Manoj Varma 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep16687
语种：English
出版社：Springer Nature
摘要：We report the implementation of a micro-patterned, glass-based photonic sensing element that is capable of label-free biosensing. The diffractive optical analyzer is based on the differential response of diffracted orders to bulk as well as surface refractive index changes. The differential read-out suppresses signal drifts and enables time-resolved determination of refractive index changes in the sample cell. A remarkable feature of this device is that under appropriate conditions, the measurement sensitivity of the sensor can be enhanced by more than two orders of magnitude due to interference between multiply reflected diffracted orders. A noise-equivalent limit of detection (LoD) of 6 × 10⁻⁷ was achieved with this technique with scope for further improvement.