Cavity Enhanced Multi-Channels Gases Raman Spectrometer

Raman spectroscopy has the advantages of multi-component detection, with a simple device and wide concentration ranges, and it has been applied in environmental monitoring and gas logging. However, its low sensitivity has limited its further applications. In fact, the Raman signal is not weak, but the utilization efficiency of the Raman signal is low, and most of the signal is wasted. Given this, in this paper we report a cavity-enhanced multi-channel gas Raman spectrometer with an eight-sided cuvette. First, we simulated the Raman scattering intensity at angles from 30 degrees to 150 degrees. The simulation results showed that the signal intensity at an angle of 45° is 1.4 times that observed at 90°. Based on the simulation results, we designed a three-channel sample cell for higher sensitivity. The results of these experiments showed that the sensitivity could be increased by adding all signal together, and the limit of detection (LOD) for CO2 was 75 ppm, which is better than that of each channel. This paper thus presents a new method to enhance the Raman signal, which can be used in field applications.

[1]  Jürgen Popp,et al.  Fiber-enhanced Raman multigas spectroscopy: a versatile tool for environmental gas sensing and breath analysis. , 2014, Analytical chemistry.

[2]  R. A. Hill,et al.  Focused, multiple-pass cell for Raman scattering. , 1974, Applied optics.

[3]  Michael Hippler,et al.  Cavity-Enhanced Raman Spectroscopy of Natural Gas with Optical Feedback cw-Diode Lasers. , 2015, Analytical chemistry.

[4]  Weigen Chen,et al.  A review of cavity-enhanced Raman spectroscopy as a gas sensing method , 2020, Applied Spectroscopy Reviews.

[5]  Kevin P. Chen,et al.  Improved sensitivity gas detection by spontaneous Raman scattering. , 2009, Applied optics.

[6]  N. E. Markina,et al.  Raman spectroscopy based analysis inside photonic-crystal fibers , 2017 .

[7]  A. Mulac,et al.  Retroreflecting multipass cell for Raman scattering. , 1977, Applied optics.

[8]  Weigen Chen,et al.  Cavity-enhanced Raman spectroscopy with optical feedback frequency-locking for gas sensing. , 2019, Optics express.

[9]  Kexin Xu,et al.  On-line multi-component analysis of gases for mud logging industry using data driven Raman spectroscopy , 2017 .

[10]  G. Keresztury.  Raman Spectroscopy: Theory , 2006 .

[11]  Johannes Kiefer,et al.  Design and characterization of a Raman-scattering-based sensor system for temporally resolved gas analysis and its application in a gas turbine power plant , 2008 .

[12]  Jürgen Popp,et al.  Fast and highly sensitive fiber-enhanced Raman spectroscopic monitoring of molecular H2 and CH4 for point-of-care diagnosis of malabsorption disorders in exhaled human breath. , 2015, Analytical chemistry.

[13]  Jinhong Guo,et al.  Performance enhancement of paper-based SERS chips by shell-isolated nanoparticle-enhanced Raman spectroscopy , 2019, Journal of Materials Science & Technology.

[14]  David J. Taylor,et al.  Enhanced Raman sensitivity using an actively stabilized external resonator , 2001 .

[15]  Li Zhan,et al.  Near-confocal cavity-enhanced Raman spectroscopy for multitrace-gas detection. , 2008, Optics letters.

[16]  Qingsheng Liu,et al.  Highly sensitive Raman system for dissolved gas analysis in water. , 2016, Applied optics.

[17]  D. Petrov,et al.  Multipass optical system for a Raman gas spectrometer. , 2016, Applied optics.