Ultrabroadband infrared nanospectroscopic imaging

Area of Science:

• Spectroscopic Imaging
• Nanoscale Microscopy
• Materials Science

Background:

• Controlling biomolecular functions, quantum matter, photonic materials, and catalysis requires nanoscale spectroscopic imaging with specificity to structure, phase, and chemical composition.
• Existing ultrahigh spatial resolution microscopy techniques often face reduced sensitivity due to increased spatial and spectral bandwidth demands.

Purpose of the Study:

• To overcome sensitivity limitations in nanoscale spectroscopic imaging.
• To develop a technique for simultaneous specificity to structure, phase, and chemical composition at nanometer resolution.
• To enable large-scale characterization and control of material heterogeneity.

Main Methods:

• Utilized infrared vibrational scattering-scanning probe near-field optical microscopy.
• Employed synchrotron mid-infrared radiation for tip-enhanced localized light-matter interaction.
• Implemented low-noise, broadband, spatially coherent synchrotron light with high spectral irradiance.
• Achieved sensitive near-field signal detection via heterodyne interferometric amplification.

Main Results:

• Achieved sub-40-nm spatially resolved molecular and phonon vibrational spectroscopic imaging.
• Enabled rapid spectral acquisition across the full mid-infrared range (700–5,000 cm(-1)) with few cm(-1) spectral resolution.
• Demonstrated subzeptomole sensitivity for vibrational chemical imaging on semiconductor, biomineral, and protein nanostructures.

Conclusions:

• Synchrotron infrared nanospectroscopy overcomes sensitivity limitations in nanoscale imaging.
• The technique provides high-resolution chemical and structural information for diverse nanomaterials.
• This advancement facilitates detailed characterization of complex matter at the nanoscale.