红外杂化单光束谱的性质

The Properties of an Infrared Hybrid Single Beam Spectrum

同一样品不同厚度(b_1和b_2)的两单光束谱ф_(b_1)和ф_(b_2)经线性组合得到杂化单光束谱ф_α=αф_(b_1)+(1-α)ф_(b_2)=αф_0e-Kb_1+(1-α)ф_0e^(-Kb_2),α为杂化系数。通过改变杂化系数α,就可获得任意强度的杂化谱ф_α。系统研究了杂化光谱ф_α的性质。研究表明,只要控制合适的条件,则厚度为(b_2-αb_2+αb_1)的真实样品的单光束谱ф_b(b=b_2-αb_2+αb_1)与杂化谱ф_α高度相似,ф_α的失真程度可忽略不计。也就是说,厚度在b_1~b_2间任一厚度b的真实样品的单光束谱都可用杂化谱ф_α来表达,ф_α≈ф_b。因此,不需制备厚度为b的样品,通过改变杂化系数α就可获得研究者所希望强度的单光束谱ф_b。杂化谱方法有望在扣除背景干扰等方面得到广泛应用。

A hybrid single beam spectrumфα=αф（b1）＋（1-α）ф（b2）=αф0e-Kb1 ＋（1-α）ф0e-Kb2 is introduced as the combination of two single beam spectraф（b1）andф（b2）from the same sample but with different pathlengths（b1and b2）,whereα（0α1）is the hybrid coefficient.The intensity of hybrid spectrumфαcan be controlled easily to the desired point by simply choosing an appropriateα.The experimental results showed that hybrid spectrumфαis very nearly identical toфb=ф0e-（-K（b2-αb2＋αbb））under appropriate conditions,namelyфα≈фb,whereфbis the single beam spectrum of the real sample with the pathlength of b2-αb2＋αb1.Therefore,the desired single beam spectrumфbcan be obtained easily by choosingαand we no longer need to prepare IR sample with the thickness of b.Hybrid spectrum method shows valuable potential in application of eliminating background interference.