【摘要】 视场角(FOV)是仅次于最大光程差、决定高分辨率傅里叶红外光谱仪(FTIRS)仪器线型函数(ILS)的重要因素。由于光学设计和装调原因,理论为圆形FOV的扩散光束,到达探测器端时,其水平和垂直方向上的FOV值往往不再严格对等。对此,提出了以椭圆形面光源取代传统文献中的圆形面光源来反映这种非对等性,并结合最大光程差参数,给出了非对等FOV作用下的高分辨率FTIRS仪器线型函数的数学和图形表述。通过比较高分辨率FTIRS实测CO标气获得的光谱,与非对等FOV、对等FOV作用下的理论光谱,发现非对等FOV作用下的理论谱与实测谱的差谱RMS值较对等FOV获得的差谱RMS值更小,在最大吸收峰附近的差谱变化更为平缓。表明了这种非对等FOV作用下的ILS函数,较对等FOV作用下的ILS函数能更精确的反映高分辨率FTIRS对谱线的真实响应。更多还原

【Abstract】 Field Of View(FOV)is an important contributor for instrumental line shape(ILS)function of high-resolution Fouriertransform infrared spectrometer(FTS)only next to maximum optical difference.For the reason of optical design and layout,commonly,the measured FOV located in detector is not regularly rounded as original one.There exits more or less difference be-tween the measured vertical FOV and measured horizontal one.In view of this case,the present paper replaces the generally cir-cular area light source with an elliptical one,which is probably more suitable for actual FTS.At the same time,the factor maxi-mum optical difference was considered.After these,the mathematic and graphic description about ILS function with unequalfield of view(UFOV)was given.Finally,comparison between measured spectrum with standard monoxide gas and calculatedone with equal field of view(EFOV)and UFOV respectively was taken.Experimental results show that the spectral residualfrom UFOV is less fluctuant than those from EFOV and its root mean square value is the smallest.All these indicate that theILS function from UFOV is more accurate and suited to reflecting the response of high-resolution FTS than the one from EFOV.更多还原