激光波长对拉曼光谱检测地质成分的影响

Effect of Laser Wavelength in Raman Spectrum Detection of Geological Components

随着激光技术的不断发展,以激光为光源的拉曼光谱检测技术由于其快速、无损、无接触探测等优势,已成为地质样品成分鉴别的一种重要途径。由于激光波长是样品拉曼效应的重要决定因素之一,进一步明确其在地质样品成分检测中的影响,能够为开展行星矿物成分研究提供重要参考。基于自主建立的532 nm/785 nm双色光源激光拉曼光谱探测系统,开展了不同激光波长对地质样品成分拉曼光谱的影响研究,获得了包括硝酸根、碳酸根、磷酸根、硅酸根等分子基团以及硫化物、氧化物等多种地质样品主要成分的拉曼特征光谱。通过对比表明,532 nm激发光具有更高的光子能量,能够检测更多的样品成分,但荧光效应较强,785 nm激发光存在拉曼信号强度较低问题,但是具有很好的荧光抑制效果,可根据实际样品种类进行最佳激发光波长的选择。

With the continuous development of laser,Raman spectroscopy detection technology based on laser sources has become an important way to identify the compositions of geological sample because of its advantages such as fast,nondestructive and contactlessdetection.The laser wavelength is one of the crucial determining factors for the Raman effect in samples.Therefore,further clarification of its impact on the detection of geological sample compositions can provide important references for planetary mineral composition research.In this study,based on a self-established 532 nm/785 nm dual-wavelength Raman spectroscopy detection system,the influence of different laser wavelengths on the spectroscopy of geological sample compositions was investigated.Characteristic Raman spectra of various geological sample major components,including nitrate,carbonate,phosphate,silicate,as well as sulfides and oxides,were obtained.A comparison indicated that 532 nm laser,due to its higher photon energy,could detect more sample components,but had a stronger fluorescence effect.On the other hand,785 nm laser faced the issue of lower Raman intensity,but had a good fluorescence suppression effect.The choice of the optimal laser wavelength could be made based on the actual types of samples.