摘要
针对光谱仪在测量窄带宽光源的光谱分布时出现的光谱变形现象,提出了一种带宽修正方法—七点修正方法。首先,利用泰勒级数和相关的导数公式,得到了七点修正公式的数学解析式;其次,用光谱线型为正弦函数的模拟光谱对七点修正法进行验证,采用正弦函数来模拟真实光谱,通过光谱仪的带宽函数计算出测量值,然后应用七点修正公式,对测量值进行修正;最后利用中心波长为365nm的LED光源对七点修正法进行了实验验证,用双光栅单色仪来测量LED光源的光谱辐射照度,光谱仪带宽分别选为5与0.5nm,将七点修正公式应用于测量值,得到修正值。模拟结果表明:在选定的模拟条件下,修正后得到的中心波长处的峰值可以达到真实值的99%以上;实验结果表明:修正后中心波长处的峰值可以达到真实值的95%以上。由模拟结果和实验结果可知,七点修正法与三点修正法和五点修正法相比,修正效果有明显提升,这种带宽修正方法可以广泛应用在光谱测量领域。
The finite bandwidth of spectroradiometers always causes significant errors when the measured light source has a narrow bandwidth compared to that of speetroradiometers. In order to solve this problem, an improved correction approach which is called seven-point correction approach is proposed. Firstly, the seven-point correction formula is obtained with Taylor＇s series and related derivative formula. Secondly, the effect of seven-point formula is validated through a simulated spectrum with a sine function shape. Considering the sine function as true spectrum, we calculate the measured spectrum with the bandpass function of spectroradiometers. We also correct the measured spectrum with the seven-point formula. At last, we validate the seven-point formula experimentally with a LED lamp whose center wavelength is 365 nm Using a double grating monochromator, we measure the irradiance of LED lamp when the bandwidth of spectroradiometer is 5 and 0. 5 nm. We also obtain the corrected spectrum by applying seven-point formula to measured spectrum. The simulated results show that, the corrected value at the center wavelength could be above 99% of the true value. The experimental results show that, the corrected value at the center wavelength could reach above 95% of the true value. Above all, the proposed seven-point approach has an improved correction effect compared with three-point and five point approach. This correction approach could he widely applied in the field of spectrum measurement.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2016年第6期1921-1924,共4页
Spectroscopy and Spectral Analysis
基金
中国博士后科学基金项目(2014M550788)
国家自然科学基金项目(41305140)资助
关键词
光谱仪
带宽函数
七点修正法
光谱分布
Spectroradiometer
Bandwidth function
Seven-point correction approach
Spectrum distribution
