Raman Gas Analysis Device Using Multimode Laser and Focusing Lens
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Solution Overview
Problem
Current gas analysis technologies, such as electrochemical sensors and optical instruments, face limitations in durability, cost, complexity, and suitability for industrial applications, particularly in providing accurate and efficient analysis of gas compositions in closed containers or for in-line processes.
Innovation Solution
A compact, cost-effective optical device for Raman spectrum analysis using a multimode laser source, a focusing lens, and a spectrograph with a beam stopper, which minimizes fluorescence and optical aberrations, and employs deconvolution techniques to enhance spectral resolution and compensate for intensity fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If absorption spectroscopy in infrared region is used for gas analysis, then molecular spectrum measurement is enabled, but detector efficiency is much lower and special materials are required
Solution Approach 1:
The patent changes the wavelength parameter from infrared to visible region, enabling the use of high-efficiency visible detectors while still achieving Raman spectrum measurement for gas analysis. This parameter change resolves the detector efficiency problem while maintaining measurement capability.
2Adaptability or versatility
If Raman spectroscopy with laser is used for gas analysis, then analysis of gases in closed containers is enabled, but fluorescence and optical aberrations affect measurement accuracy
Solution Approach 1:
The patent extracts and removes the harmful fluorescence component from the detected signal through spectral processing, isolating the Raman spectrum from the fluorescence background. This enables accurate Raman measurement in closed containers despite the presence of fluorescence interference.
Solution Approach 2:
The patent introduces deconvolution processing as an intermediary step between signal detection and final analysis. This mathematical processing acts as a mediator to separate overlapping spectral components and correct optical aberrations, improving spectral resolution.
3Measurement precision
If conventional Raman spectroscopy setup is used, then gas analysis is possible, but optical components and alignment complexity increase device complexity
Solution Approach 1:
The patent uses a standard spectrograph designed for general spectral analysis and adapts it for Raman gas analysis. The spectrograph performs multiple functions including wavelength dispersion, fluorescence rejection, and Raman signal detection, reducing the need for specialized optical components and simplifying the overall device.
Data Source
Figure 1~2c
Figure 3
Figure 4~6
AI summary
Device (12) for analyzing the gas composition, of an optical type, characterized in that it comprises: - an exciting radiation emitter (14) comprising a multimode laser source (16) configured to emit a laser beam; - an analysis cell (18) suitable for containing a gas, said analysis cell (18) having an inlet duct (20), through which a gas can flow inside said analysis cell (18), and a outlet duct (22), through which the gas can flow from the analysis cell (18); said analysis cell (18) comprising a focusing lens (24), suitable for focusing said laser beam in a focal area (26) inside the analysis cell (18), said focal area (26) acting as a source for radiation Raman collected in a direction perpendicular to the direction of the beam, said analysis cell (18) comprising a window (27) and/or lens suitable to be crossed by said Raman radiation, - an imaging group (28) of the Raman source and a spectrograph (30); said imaging group being suitable for forming an image of the Raman source input to said spectrograph (30); and - a detector (32) suitable for collecting the image of the spectrum formed by the spectrograph (30), and also characterized in that the seal for the gas inside said analysis cell (18) is obtained, in correspondence with the entry of the laser beam into the same analysis cell (18), by means of said focusing lens (24).