Dual-Comb Real-Time Molecular Fingerprint Imaging

TL;DR

This paper demonstrates real-time, scan-free hyperspectral imaging in the near-to-mid-infrared using dual frequency combs and a high-frame-rate detector array, enabling rapid molecular fingerprint imaging.

Contribution

It introduces a novel dual-comb hyperspectral imaging system that operates in the infrared with uncooled detectors, leveraging high mutual coherence and AI for real-time data processing.

Findings

Achieved hyperspectral imaging across 30 spectral channels and 16,384 pixels.

Enabled real-time molecular gas concentration imaging.

Demonstrated operation in the 1-5 μm wavelength range.

Abstract

Hyperspectral imaging provides spatially resolved spectral information. Utilising dual frequency combs as active illumination sources, hyperspectral imaging with ultra-high spectral resolution can be implemented in a scan-free manner when a detector array is used for heterodyne detection. However, relying on low-noise detector arrays, this approach is currently limited to the near-infrared regime. Here, we show that dual-comb hyperspectral imaging can be performed with an uncooled near-to-mid-infrared detector by exploiting the detector array's high frame-rate and the combs' high-mutual coherence. The system simultaneously acquires hyperspectral data in 30~spectral channels across 16'384 pixel, from which molecule-specific gas concentration images can be derived. Artificial intelligence enables rapid data reduction and real-time image reconstruction. Owing to the detector array's sensitivity from 1~$\mu$m to 5~$\mu$m wavelength, this demonstration lays the foundation for versatile imaging of molecular fingerprint signatures across the infrared wavelength-regime in real-time.