-
摘要
本文提出了一种中心波长连续可调的光源模块,实现了深紫外光源的窄带输出。设计的光源模块由氘灯、角度旋转台、滤光片旋转轮、不同中心波长的滤光片(220 nm,230 nm,240 nm,250 nm,260 nm,270 nm,280 nm)和光学透镜组成。基于多光束干涉理论,通过分析出射光的中心波长和入射角度之间的关系,得到了由每个滤光片出射的中心波长和角度旋转台旋转角度之间的定标关系式。实验结果表明,当角度旋转台入射角范围在0~30°时,每个滤波片的可调谐范围可达到10 nm,实现紫外光源模块的单色光可调谐范围212 nm~280 nm,能满足海水中硝酸盐浓度的测量要求。
Abstract
A deep UV tunable narrow-passband light source module for the nitrate measurement system is proposed and demonstrated in this paper. The module consists of a deuterium lamp, an angle rotation stage, a motorized filter wheel, the deep UV optical filters with different central wavelengths, as well as the collimating lens. Seven UV filters with different central wavelengths of 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm and 280 nm are placed on the filter wheel. Based on the principle of multiple-beam interference, the central wavelength of the transmission light and the rotation angle are regressed and calibrated to obtain the relationship model. The experiment results demonstrate that with the rotation angle from 0 to 30°, each filter can realize wavelength tuning range of 10 nm. In addition, the designed deep UV tunable light source module can obtain monochromatic light with the wavelength ranging from 212 nm to 280 nm, which meets the measurement requirements of the nitrate in seawater.
-
Overview
Overview: Nitrate is the mainly form of existence of nitrogen in seawater and is related to the outbreak of red tides. The ultraviolet (UV) absorption spectroscopy based on Lambert Beer law is one of the major technologies of nitrate measurement. This technology has a high requirement for the monochromaticity of light source. However, the present commercial nitrate sensors, including SUNA, utilize the broadband light source, which may lead to measurement errors. Therefore, it is important to design a new UV tunable light source with monochromaticity for the nitrate measurement system. Currently, both UV Laser Diode (LD) and UV Light Emitting Diode (LED) are the widely used UV light sources, but they are not suitable for the long-term and in-situ nitrate measurement system due to the low power of these light sources. Deuterium lamp, as a kind of UV gas light source with high power and stability, is a good choice to obtain monochromatic lights with different filters. This paper proposes a new UV tunable light source module based on the principles of Fabry-Perrot interference and multiple-beam interference. This light source module could obtain continuously adjustable ultraviolet light by changing the angles between the incident light and the filters. The module consists of a deuterium lamp, horizontal and vertical rotating tables, UV optical filters with different central wavelengths, and collimating lens. The filters are placed in the horizontal rotating table which has the filter capacity. UV narrowband light with different central wavelengths could be obtained by changing the position of the vertical rotating table. The horizontal rotating table is utilized to change the angles between the incident light and filters. The UV tunable light source has 7 optical filters with central wavelengths of 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm and 280 nm respectively. The experiment results demonstrate that with the rotation angle from 0 to 30°, each filter can realize wavelength tuning range of 10 nm, and the designed deep UV tunable light source module can obtain monochromatic light with the wavelength ranging from 212 nm to 280 nm. With the presented new light source module and the data processing method, the absorbance spectrum is smoother and more distinguishable than those with broadband light source. This paper proposes a reliable method to realize the UV tunable light source module for the nitrate measurement system and verifies the feasibility of this system. This work can provide the integration and optimization of the nitrate sensor with technical supports.
-
-
表 1 不同紫外滤光片基于式(12)计算的拟合参数
Table 1. Fitting parameters of the equation (12) of different UV filters
Filter 220 nm 228 nm 239 nm 250 nm 260 nm 270 nm 280 nm λ0 221.99 229.78 240.45 251.25 261.83 270.89 279.70 n/N 0.6808 0.7302 0.7548 0.6590 0.7662 0.7564 0.7809 D0 3.0762 5.9561 6.5074 4.3775 8.0196 6.4473 6.6042 Central wavelength calibration error/% 0.904 0.781 0.607 0.500 0.704 0.330 0.107 -
参考文献
[1] 王雪霁, 胡炳樑, 于涛, 等. 基于LLE-BPNN的小麦岛海水硝酸盐含量分析[J]. 光谱学与光谱分析, 2019, 39(5): 1503-1508. https://www.cnki.com.cn/Article/CJFDTOTAL-GUAN201905034.htm
Wang X J, Hu B L, Yu T, et al. Analysis of nitrate in seawater of wheat island based on LLE-BPNN[J]. Spectrosc Spect Anal, 2019, 39(5): 1503-1508. https://www.cnki.com.cn/Article/CJFDTOTAL-GUAN201905034.htm
[2] 潘俊, 于非, 任强, 等. 基于光学传感器在南黄海硝酸盐调查中的使用初探[J]. 海洋科学, 2017, 41(12): 9-16. doi: 10.11759/hykx20170510001
Pan J, Yu F, Ren Q, et al. Reliability analysis of spatial and temporal nitrate variations estimated by SUNA in the South Yellow Sea[J]. Mar Sci, 2017, 41(12): 9-16. doi: 10.11759/hykx20170510001
[3] Ogura N, Hanya T. Nature of ultra-violet absorption of sea water[J]. Nature, 1966, 212(5063): 758. doi: 10.1038/212758a0
[4] Zhu X Y, Yu K X, Zhu X F, et al. An improved algorithm for measuring nitrate concentrations in seawater based on deep-ultraviolet spectrophotometry: a case study of the Aoshan bay seawater and western pacific seawater[J]. Sensors, 2021, 21(3): 965. doi: 10.3390/s21030965
[5] 叶江雷, 吴云辉, 苏秋芳, 等. 光度法检测地表水中硝酸盐氮、亚硝酸盐氮对朗伯-比尔定律的偏离[J]. 福建水产, 2015, 37(5): 396-391. https://www.cnki.com.cn/Article/CJFDTOTAL-FJSC201505007.htm
Ye J L, Wu Y H, Su Q F, et al. The deviation of the Lambert-Bill law from determination of NO3--N, NO2--N in surface water by spectrophotometry[J]. J Fujian Fish, 2015, 37(5): 396-391. https://www.cnki.com.cn/Article/CJFDTOTAL-FJSC201505007.htm
[6] Poornima D, Shanthi R, Ranith R, et al. Application of in-situ sensors (SUNA and thermal logger) in fine tuning the nitrate model of the Bay of Bengal[J]. Remote Sens Appl: Soc Environ, 2016, 4: 9-17. http://www.sciencedirect.com/science/article/pii/S235293851630026X
[7] Snazelle T T. Results from laboratory and field testing of nitrate measuring spectrophotometers[R]. Reston, VA: U. S. Geological Survey, 2015: 1-15.
[8] Sakamoto C M, Johnson K S, Coletti L J. Improved algorithm for the computation of nitrate concentrations in seawater using an in situ ultraviolet spectrophotometer[J]. Limnol Oceanogr: Methods, 2009, 7(1): 132-143. doi: 10.4319/lom.2009.7.132
[9] Zielinski O, Voβ D, Saworski B, et al. Computation of nitrate concentrations in turbid coastal waters using an in situ ultraviolet spectrophotometer[J]. J Sea Res, 2011, 65(4): 456-460. doi: 10.1016/j.seares.2011.04.002
[10] 朱笑凡. 基于深紫外波长可调光源的海水硝酸盐测量装置[D]. 济南: 山东大学, 2020.
Zhu X F. Seawater nitrate measurement device based on deep ultraviolet wavelength adjustable light source[D]. Ji'nan: Shandong University, 2020.
[11] Shaw G A, Siegel A M, Model J, et al. Recent progress in short-range ultraviolet communication[J]. Proc SPIE, 2005, 5796: 214-225. doi: 10.1117/12.603196
[12] 物理光学[M]. 4版. 北京: 电子工业出版社, 2012.
[13] 黄腾超, 陈海星, 李海峰, 等. 可调谐液晶法-珀滤光片的研究[J]. 光子学报, 2003, 32(12): 1438-1441. https://www.cnki.com.cn/Article/CJFDTOTAL-GZXB200312007.htm
Huang T C, Chen H X, Li H F, et al. A research on tunable liquid crystal Fabry-Perot filter[J]. Acta Photonica Sin, 2003, 32(12): 1438-1441. https://www.cnki.com.cn/Article/CJFDTOTAL-GZXB200312007.htm
[14] Murali A, Kakarla H K, Priyadarshini G M A. Improved design debugging architecture using low power serial communication protocols for signal processing applications[J]. Int J Speech Technol, 2021, 24(2): 291-302. doi: 10.1007/s10772-020-09784-x
[15] 闫啸, 李树江, 王向东. 基于嵌入式Linux与Qt的植保机流量控制器设计与实现[J]. 计算机测量与控制, 2019, 27(10): 95-99. https://www.cnki.com.cn/Article/CJFDTOTAL-JZCK201910020.htm
Yan X, Li S J, Wang X D. Design and implementation of flow controller of plant protection machine based on embedded Linux and Qt[J]. Comput Meas Control, 2019, 27(10): 95-99. https://www.cnki.com.cn/Article/CJFDTOTAL-JZCK201910020.htm
[16] Nguyen C V, Le Quang T, Vu T N, et al. A non-contact infection screening system using medical radar and Linux-embedded FPGA: implementation and preliminary validation[J]. Inform Med Unlocked, 2019, 16: 100225. doi: 10.1016/j.imu.2019.100225
-
访问统计