Spatial-heterodyne spectrometer for transmission-Raman observations

Area of Science:

• Spectroscopy
• Analytical Chemistry
• Optical Instrumentation

Background:

• Traditional Raman spectrometers face limitations in light collection efficiency.
• Spatial heterodyne spectroscopy (SHS) offers high etendue, improving light throughput.
• Developing advanced spectroscopic tools is crucial for sensitive chemical analysis.

Purpose of the Study:

• To develop and characterize a new transmission Raman spectrometer based on spatial heterodyne spectroscopy (SHS).
• To evaluate the performance of the SHS-based Raman spectrometer for analyzing solid samples.
• To assess the impact of fiber optic coupling on spectral resolution and signal collection.

Main Methods:

• Design and construction of a transmission Raman spectrometer incorporating an SHS.
• Testing the spectrometer's performance using paracetamol tablet samples.
• Characterization of light collection capabilities using fiber optic bundles of varying core diameters and numerical apertures.

Main Results:

• The developed spectrometer successfully utilizes the high etendue of SHS to maximize light collection.
• The instrument demonstrated effective analysis of paracetamol tablet samples.
• No degradation in spectral resolution was observed across a range of fiber core diameters (0.05 mm to 3 mm) and numerical apertures (0.22).

Conclusions:

• The novel SHS-based transmission Raman spectrometer is a viable and high-performance analytical tool.
• The system's ability to maintain resolution while accepting significant light throughput makes it suitable for various applications.
• This development advances spectroscopic techniques for efficient and accurate chemical analysis.