Single-Shot Standoff Hyperspectral Raman Imaging of a Chemical Warfare Agent Simulant

Area of Science:

• Chemical analysis
• Spectroscopy
• Imaging techniques

Background:

• Hyperspectral Raman imaging provides detailed chemical information.
• Standoff detection is crucial for remote chemical identification.
• Evaluating imaging techniques for standoff chemical analysis is important.

Purpose of the Study:

• To demonstrate and compare two techniques for single-shot standoff hyperspectral Raman imaging.
• To assess the performance of multi-bandpass filter imaging (MBFI) and fiber-bundle imaging spectroscopy (FBIS).
• To determine optimal parameters for FBIS at a standoff distance.

Main Methods:

• Single-shot standoff hyperspectral Raman imaging was performed at 1m.
• Multi-bandpass filter imaging (MBFI) utilized commercial filters.
• Fiber-bundle imaging spectroscopy (FBIS) employed a fiber optic bundle.

Main Results:

• MBFI achieved good spatial resolution but poor spectral resolution.
• FBIS provided excellent spectral resolution but limited spatial resolution.
• A minimum pump fluence of 10 mJ/cm² was determined for FBIS at 1m.

Conclusions:

• FBIS is superior for spectral resolution in standoff Raman imaging.
• MBFI is better suited when spatial resolution is prioritized over spectral detail.
• FBIS requires specific laser fluence for effective single-shot data acquisition.