提出了一种实现光声光谱的导数光谱的新方法,为了获得光声光谱的导数光谱,利用一台单色仪和一个分光棱镜研制成一个波长光强分束器,并用这个波长光强分束器同时获得两束光强相等而波长有微小差别的两束光,这两束光经过一个互补调制器调制后在光声探测器内叠加,可以实现光声信号的差分,扫描单色仪的波长,就可以获得光声吸收光谱的导数光谱。实验证明这种方法可以准确实现光声光谱的一阶导数光谱,而且导数光声光谱比光声吸收光谱具有更高的光谱分辨率。

A new method for obtain the derivative photoacoustic spectroscopy is proposed. A wavelength-intensity splitter is designed to obtain the derivative spectroscopy of photoacoustic spectroscopy with the help of a monochromator and a prism. Using the wavelength-intensity splitter, two light beams with identical intensity but lightly different are obtained in wavelenth at the same time. The two light beams are modulated and then folded in the photoacoustic detector symmetrically, so as to realize the difference of phtoacoustic signal. The derivative photoacoustic spectra is obtained by scanning the wavelength of monochromator. The first-order derivative spectra of photoacoustic spectra is obtained with the method. The derivative photoacoustic spectroscopy is endowed with higher resolution than that of photoacoustic spectroscopy.