Dual-comb mid-infrared spectromicroscopy with photothermal fluorescence detection

Area of Science:

• Spectroscopy and Imaging
• Quantum Cascade Lasers
• Mid-Infrared Optics

Background:

• Direct infrared transmission imaging offers high spectral detail but suffers from low spatial resolution due to long wavelengths.
• Fluorescence-detected photothermal infrared (F-PTIR) imaging provides high spatial resolution linked to IR absorption.

Purpose of the Study:

• To develop a hyperspectral mid-infrared imaging method with high spatial and spectral resolution.
• To integrate the strengths of dual-comb spectroscopy and F-PTIR imaging.

Main Methods:

• Utilized quantum cascade laser (QCL)-based dual-comb mid-infrared spectroscopy for rapid spectral acquisition (<1 ms).
• Employed fluorescence-detected photothermal infrared (F-PTIR) imaging for high spatial resolution.
• Applied a multi-agent consensus equilibrium (MACE) computational imaging approach to combine both techniques.

Main Results:

• Achieved spectrally parallel hyperspectral mid-infrared imaging.
• Demonstrated high-speed spectral mapping capabilities in microscopy.
• Successfully combined high spatial resolution (F-PTIR) with high spectral information (dual-comb transmission).

Conclusions:

• The developed approach creates an optimized hyperspectral data cube by merging high spatial and spectral resolution.
• This technique enhances the analysis of mid-infrared spectral information with precise spatial localization.