Combustion Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden.
Appl Spectrosc. 2010 Aug;64(8):964-6. doi: 10.1366/000370210792081145.
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) (approximately 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.
杂散光干扰是自发旋转拉曼光谱和旋转相干反斯托克斯拉曼光谱（CARS）中的一个常见问题。原因是检测到的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很难抑制。在本说明中，通过使用市售的短波长通滤波器，对旋转 CARS 测量中的杂散光进行了有效的抑制。通过以 561nm 的特定截止波长角度调节该滤波器，可以将截止波长调谐到所需的光谱位置，从而在距离探测光束波长 532.0nm 约 15cm(-1)（约 0.4nm）处实现超过 80%的透射率，同时在该波长处的强度降低两个数量级。
