实验不可分辨的Voigt线型重叠谱线的压致展宽线宽的偏差确定

通过仿真和拟合Voigt线型重叠谱线，讨论了将实验上不可分辨的两条谱线重叠后视为单条谱线时所得到的压致展宽线宽与其实际值的相对误差ε，分析了该误差与两谱线的中心位置距离δν₀和实际的压致展宽线宽δν0_Ｌ的变化规律。发现ε在谱线的压致展宽线宽远小于多普勒线宽δν_Ｄ时显得很大，与δν₀和δν0_Ｌ的变化规律较复杂;当δν0_Ｌ可与δν_Ｄ比拟时，ε随δν₀的变化趋于呈光滑的二次项函数曲线，但曲线的斜率在δν0_Ｌ小于δν_Ｄ情况下为负，而在δν0_Ｌ大于δν_Ｄ时为正。整体来说，随着δν0_Ｌ对总线宽的影响越大，ε越小。所有这些结论和相应关系数据为修正压致展宽线宽的拟合值具有积极的参考价值，并且为进一步从实验上不可分辨的重叠谱线确定精确的压致展宽系数提出了极有意义的方法和思路。

Determination of Relative Error of Pressure-Broadening Linewidth for the Experimentally Indistinguishable Overlapped Spectral Lines with Voigt Profile

The simulation and fitting of the overlapped spectral lines with Voigt profile were presented in this paper. The relative errors epsilon of the fitted pressure-broadening linewidth when taking the overlapped spectral line as one spectrum were discussed in detail. The relationship between such error and the two spectral lines center distance deltav0, and theoretical pressure-broadening linewidth deltav(L)0 were analyzed. Epsilon is found to be very large and the relationship between epsilon and deltav0, deltav(L)0 is very complicated when the value of pressure-broadening linewidth is considerably less than that of Dopplerian one deltavD. When deltav(L)0 is comparative to deltaVD the relationship between epsilon and deltav0 is close to the smooth two-order polynomial curve. However, the slop of this curve is negative while deltav(L)0 is smaller than deltavD and is positive when larger. Generally, epsilon decreases with the increase of proportion of deltav(l)0 to the whole spectral linewidth. All the above conclusion and corresponding data are the significant reference to determine the precise pressure-broadening coefficient from the experimentally indistinguishable overlapped spectrum, as well as to correct the fitted pressure-broadening linewidth.