0.2～1.8THz波段豆油光谱特性的快速检测  

Rapid Measurement of Spectral Characteristics of Soybean Oil in 0.2-1.8THz Range

作　　者：周胜灵[1] 祝诗平[1] 李光林[1] 黄杰[1] 袁嘉佑 ZHOU Sheng-ling ZHU Shi-ping LI Guang-lin HUANG Jie YUAN Jia-you(School of Engineering and Technology, Southwest University, Chongqing 400715, China)

机构地区：[1]西南大学工程技术学院,重庆400715

出　　处：《西南大学学报（自然科学版）》2017年第2期165-170,共6页Journal of Southwest University(Natural Science Edition)

基　　金：国家自然科学基金项目(61401373);中央高校基本科研业务费专项资金项目(2362014xk13);重庆市应用开发计划项目(cstc2014yykfa80006)

摘　　要：针对液体样品在太赫兹光谱检测中遇到的比色皿吸收及频谱振荡问题,以豆油检测为例,在传统计算模型基础上,考虑石英比色皿对THz电磁波吸收,建立THz-TDS技术提取液体材料吸收系数和折射率的计算模型,并对得到的光谱数据利用小波变换进行时-频分析,找出频谱、吸收谱振荡的原因,采用主脉冲截取法,有效去除发射器、探测器以及石英比色皿等光学元件Etalon效应引起的频谱干涉,最后,结合实验得到的0.2~1.8THz波段豆油频谱对采用的主脉冲截取法的优缺点进行分析,并深入探讨1.0~1.8THz频段样品吸收谱、频谱残余振荡存在的原因.该测量分析方法对THz光谱技术在食用油品质检测应用方面进行了有益探索.In order to solve the problems encountered in Terahertz（THz）spectroscopy detection of liquid samples,THz electromagnetic wave signal attenuation caused by the quartz cuvette and oscillation spectrum produced by Etalon effect,a study was made taking soybean oil detection as an example.On the basis of traditional algorithm for extracting solid material parameters from measured THz waveforms,the influence of quartz was considered,and a new model for calculating the optical parameters of the liquid material was established.By wavelet transform the spectral data obtained was transformed into time-frequency plane and the reason of the spectrum oscillation was analyzed.Then,for reducing these oscillations arising from the Etalon effect in optical elements,a simple algorithm,the main pulse interception,was introduced into signal processing;some improvement on the traditional computing model was made.The results showed that this algorithm can successfully remove Etalon oscillations from the frequency-domain data.Finally,combined experimental spectrum data in 0.2-1.8THz,the strengths and weaknesses of this algorithm were discussed in depth and the reasons for the occurrence of residual oscillation in 1.0-1.8THz band were explored.The measurement and analysis method employed herein should be helpful for the improvement of THz spectroscopy applications in edible oil quality testing.

关 键 词：太赫兹 Etalon效应 时-频分析 主脉冲截取法 豆油 

分 类 号：O433[机械工程—光学工程] O439[理学—光学]