【摘要】 报道一种改进的受激喇曼光声光谱实验方法 (PhotoacousticRamanSpectroscopy ,PARS) ,该方法的主要特点是将两束激光以反向传播的方式重合 ,从而不仅克服了通常的实验方法 (两束激光通过双色镜片重合 )在测量小喇曼位移方面的限制 ,也使实验的操作更加简单 .在实验中 ,以CH4 分子为研究对象 ,一束波长为 5 3 2 .1nm的激光作为泵浦光 ,另一束可调谐激光作为探测光 (Stokes光 ) ,两束光相向作用于光声池内 ,在 62 5～ 64 2nm和 5 73～ 5 89nm得到了CH4 分子ν1 、ν2 和ν3模的PARS光谱 ,其结果与前人利用自发喇曼散射技术 (ORS)一致 ,其中喇曼活性较弱且喇曼位移较小的ν2 模的PARS光谱是新得到的更多还原

【Abstract】 An improved experiment setup for Stimulated Photoacoustic Raman Spectroscopy (PARS) was reported. The employed two laser beams, unlike general arrangement of propagating in the same direction, counterpropagated with each other. This arrangement can eliminate the limitation that the small Raman shift could not be measured with general arrangement. Therefore, this improved setup was especially useful for measuring the PARS spectrum with small Raman shift, such as the pure rotational Raman spectrum. In the experiment, taking CH 4 molecules as a research object, one laser was fixed at 532.1 nm while another tunable dye laser scanned. The PARS spectrum of CH 4 molecules for the ν 1, ν 2 and ν 3 bands was recorded in the two wavelength ranges of 625～642 nm and 573～589 nm, and the results agreed well with those obtained by Spontaneous Raman Scattering (ORS) technique, confirming the validity of the improved experimental setup.更多还原