| 1. |
- Dong, Yongjiang, et al.
(författare)
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LED-induced fluorescence system for tea classification and quality assessment
- 2014
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Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774. ; 137, s. 95-100
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Tidskriftsartikel (refereegranskat)abstract
- A fluorescence system was developed by using several light emitting diodes (LEDs) with different wavelengths as excitation light sources. The fluorescence sensor head consists of multi LED light sources and a multimode fiber for fluorescence collection, where the LEDs and the corresponding filters can be easily chosen to get appropriate excitation wavelengths for different applications. By analyzing fluorescence spectra with the principal component analysis method, the system was utilized in the classification of four types of green tea and two types of black tea beverages. Quality of Xihu Longjing tea leaves of different grades and that of the corresponding liquid tea samples were studied to further investigate the ability and application of the system in the evaluation of classification/quality of tea and other foods. (C) 2014 Elsevier Ltd. All rights reserved.
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| 2. |
- Li, Jingwei, et al.
(författare)
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A portable confocal hyperspectral microscope without any scan or tube lens and its application in fluorescence and Raman spectral imaging
- 2017
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018 .- 1873-0310. ; 392, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a portable confocal hyperspectral microscope is developed. In traditional confocal laser scanning microscopes, scan lens and tube lens are utilized to achieve a conjugate relationship between the galvanometer and the back focal plane of the objective, in order to achieve a better resolution. However, these lenses make it difficult to scale down the volume of the system. In our portable confocal hyperspectral microscope (PCHM), the objective is placed directly next to the galvomirror. Thus, scan lens and tube lens are not included in our system and the size of this system is greatly reduced. Furthermore, the resolution is also acceptable in many biomedical and food-safety applications. Through reducing the optical length of the system, the signal detection efficiency is enhanced. This is conducive to realizing both the fluorescence and Raman hyperspectral imaging. With a multimode fiber as a pinhole, an improved image contrast is also achieved. Fluorescent spectral images for HeLa cells/fingers and Raman spectral images of kumquat pericarp are present. The spectral resolution and spatial resolutions are about 0.4 nm and 2.19 mu m, respectively. These results demonstrate that this portable hyperspectral microscope can be used in in-vivo fluorescence imaging and in situ Raman spectral imaging.
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| 3. |
- Yong, Zhengdong, et al.
(författare)
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Broadband Nanoantennas for Plasmon Enhanced Fluorescence and Raman Spectroscopies
- 2015
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Ingår i: Progress In Electromagnetics Research. - : EMW Publishing. - 1070-4698 .- 1559-8985. ; 153, s. 123-131
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Tidskriftsartikel (refereegranskat)abstract
- We propose a novel design of broadband plasmonic nanoantenna that is suitable for fluorescence and Raman enhancement. The structure consists of a gold nanoring and bowties at the center. We numerically investigate the near field and far field performance by employing the finite-difference time-domain method. High Purcell enhancement and large SERS are demonstrated in a record wide spectral bandwidth of 700 nm based on a single emitter-antenna configuration. Moreover, unlike a traditional antenna design, the proposed nanoantenna has low heat generation and high field enhancement at the gap simultaneously when operating off resonance.
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