High-resolution, broad-spectral-range Raman measurement using a spatial heterodyne spectrometer with separate filters...

Area of Science:

• Spectroscopy
• Analytical Chemistry
• Materials Science

Background:

• Raman spectroscopy is a powerful technique for molecular identification.
• Existing Raman spectrometers often face limitations in resolution, spectral range, or sensitivity.
• Fluorescence interference can obscure weak Raman signals, hindering analysis.

Purpose of the Study:

• To develop and demonstrate a high-resolution, broad-spectral-range spatial heterodyne Raman spectrometer (SHRS).
• To enhance signal-to-noise ratios and improve the visibility of weak Raman peaks.
• To assess the performance of the spectrometer for analyzing diverse chemical compounds and materials.

Main Methods:

• A prototype spatial heterodyne Raman spectrometer (SHRS) was constructed utilizing separate filters and multi-gratings (SFMG).
• The SFMG design incorporates four sub-gratings with varying groove densities (320, 298, 276, 254 gr/mm) and corresponding filter bands.
• Raman spectra were acquired for inorganic and organic compounds, microplastics, and mixtures under varied experimental conditions (integration time, laser power, containers).

Main Results:

• The SFMG-SHRS demonstrated high-resolution and broad-spectral-range Raman measurements.
• Improved signal-to-noise ratios were achieved compared to conventional methods.
• Enhanced visibility of weak Raman peaks was observed, even in the presence of significant fluorescence.

Conclusions:

• The designed SFMG-SHRS is effective for high-performance Raman spectroscopic analysis.
• The spectrometer offers significant advantages for identifying and characterizing a wide range of chemical substances.
• This technology holds promise for applications requiring sensitive and detailed molecular analysis.