宽波段光源在工作过程中, 光强通常会随供电电源输出功率的变化而波动。 宽波段光源波段内各个波长的光谱强度将会发生不同程度的波动。 为解决光源光强波动时其波段内各个波长光谱强度的补偿问题, 提出了一种基于光谱线性拟合的补偿方法。 使用这种方法, 只需测量光源波段光强的变化, 就可以补偿各个波长光谱强度的波动。 通过分析理想黑体全波段辐射出射度与光谱辐射出射度的近似线性关系。 建立了宽波段光源波段光强与光谱强度的线性模型。 实验装置主要由卤素灯珠、 光源电源、 光阑、 光谱仪及计算机构成。 调节电源的输出功率, 得到一组卤素灯珠在不同输入功率下的相对光谱强度。 测量不同功率下卤素灯珠光谱强度来验证该方法补偿效果。 按线性关系拟合了卤素灯珠光谱强度与其波段光强关系式, 并分析了拟合误差。 实验表明: 卤素灯珠的光谱强度与其波段光强具有很好的线性关系, 可以用波段光强按线性关系来补偿其光谱强度的波动。 随着卤素灯珠输入功率的增大, 补偿后的光谱强度的相对误差绝对值下降。 在卤素灯珠输入功率范围内, 使用该方法补偿的光谱强度在绝大部分(92%)波长下相对误差绝对值可在5%以内。

The intensity of broadband illuminant fluctuates when its power supply output power changes. Spectral intensities at each wavelength within the band of broadband illuminant fluctuate at different levels. A method based on spectrum linear fitting is proposed to compensate the illuminant spectral intensity in its band when its intensity fluctuates. The spectral intensity fluctuation at each wavelength could be compensated simply by measuring the band intensity with this method. The linear relationship between spectral radiant exitance and whole radiant exitance of ideal blackbody was analysed by researching the radiant exitance at different temperatures. The linear model of broadband illuminant band intensity and spectral intensity was built. Experimental system is composed of a halogen light, a power supply, an aperture, a spectrometer, and a computer mainly. By adjusting the power output of the power supply, we obtained a set of halogen light relative spectral intensities at different power inputs. The spectral intensity of halogen light at different input powers was measured to test the compensation effect of this method. The relationship between spectral intensity and band intensity of halogen light was fitted with linear relation and the fitting errors were analysed. The experimental result shows a linear relationship between spectral intensity and band intensity of halogen light, so the spectral intensity fluctuation can be compensated using the band intensity according to their linear relation. The relative error absolute value of compensated spectral intensity decreases as the halogen light input power increases. Within the range of halogen light input power, the relative error absolute values of spectral intensity compensated with this method are within 5% at vast majority (92%) of the wavelengths.