Wide Absorption Spectrum Measuring Methods by DFB-LDs in Water Vapor Detection System  

作　　者：Y. N. LIU J. CHANG J. LIAN Q. WANG G. P. LV W. J. WANG Z. LIU X. Z. LIU S. S. ZHANG Z. L. WANG S. JIANG C. G. ZHU W. WEI B.N. SUN 

机构地区：[1]School of Information Science and Engineering and Shandong Provincial Key Laboratory of Laser Technology andApplication, Shandong University, Jinan, 250100, China [2]Institute of Automation, Shandong Academy of Sciences, Jinan, 250014, China

出　　处：《Photonic Sensors》2014年第3期230-235,共6页光子传感器（英文版）

基　　金：This work was supported by Natural Science Foundation of China （60977058 ＆ 61205083）, Independent Innovation Foundation of Shandong University （IIFSDU2010JC002 ＆ 2012JC015）, the key technology projects of Shandong Province （2010GGX10137）, and promotive research fund for excellent young and middle-aged scientists of Shandong Province （BS2010DX028）. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author（s） and source are credited.

摘　　要：Two measuring methods of the wide absorption spectrum by distributed feedback laser diodes （DFB-LDs） are presented in detecting the water vapor absorption line. One is the subsection scanning method, and it takes advantage of the wide spectrum tuning range by the temperature modulation and fast spectrum tuning speed by current modulation. Specifically, this method is realized by dividing a target spectral region into several sections which correspond to the specific temperature of DFB-LD, scanning every section by current modulation for hundreds times, and averaging the data to raise the signal to noise ratio （SNR）, then combining all sections to get the whole spectrum. An accuracy of 10ppmv had been obtained in the measurement of water vapor with a 10-cm path length by this method. Another is data fitting method, based on the absorption line-shape function; the absorption line can be described by fitting with partial measured data. The fitting absorption line was fitted well with the measured data, and the square of correlation coefficient （R-square） was no less than 0.99.

关 键 词：DFB-LD wide spectrum subsection scanning data fitting water vapor detection 

分 类 号：TN242[电子电信—物理电子学] O734[理学—晶体学]