Effective Suppression of Stray Light in Rotational Coherent Anti-Stokes Raman Spectroscopy Using an Angle-Tuned Short-Wave-Pass Filter
Effective Suppression of Stray Light in Rotational Coherent Anti-Stokes Raman Spectroscopy Using an Angle-Tuned Short-Wave-Pass Filter
复制标题
使用角度调谐短波通滤波器有效抑制旋转相干反斯托克斯拉曼光谱中的杂散光
作者：
A. Bohlin;P. Bengtsson
杂散光干扰是自发转动拉曼光谱和转动相干反斯托克斯拉曼光谱（汽车）中普遍存在的问题。其原因在于，检测光谱出现在探测光束波长的光谱附近，并且来自光学器件和表面的该波长的杂散光难以抑制。在本说明中，使用市售短波通滤波器证明了旋转汽车测量对杂散光的有效抑制。通过在561 nm处的特定截止波长对该滤波器进行角度调谐，截止波长可以被调谐到所需的光谱位置，使得在距离532.0 nm的探测光束波长15 cm−1（约0.4 nm）处实现超过80%的透射率，同时该波长处的强度被抑制两个数量级。
Stray light interference is a common problem in spontaneous rotational Raman spectroscopy and rotational coherent anti-Stokes Raman spectropscopy (CARS). The reason is that the detected spectrum appears in the spectral vicinity of the probe beam wavelength, and stray light at this wavelength from optics and surfaces is hard to suppress. In this Note, efficient suppression of stray light is demonstrated for rotational CARS measurements using a commercially available short-wave-pass filter. By angle-tuning this filter with a specified cut-off wavelength at 561 nm, the cut-off wavelength could be tuned to a desired spectral position so that more than 80% transmission is achieved as close as 15 cm−1 (∼0.4 nm) from the probe beam wavelength of 532.0 nm, while the intensity at this wavelength is suppressed by two orders of magnitude.