Phase-Sensitive Vibrationally Resonant Sum-Frequency Generation Microscopy in Multiplex Configuration at 80 MHz...

Area of Science:

• Spectroscopy
• Microscopy
• Biophysics

Background:

• Vibrationally resonant sum-frequency generation (VR SFG) microscopy offers high-resolution imaging of vibrational modes.
• Current limitations include slow acquisition speeds, hindering detailed molecular analysis.

Purpose of the Study:

• To develop a high-speed VR SFG hyperspectral imaging platform for enhanced molecular-level understanding of biological systems.
• To enable rapid microspectra measurements at each pixel for detailed structural analysis.

Main Methods:

• Implementation of an ultrafast laser system at an 80 MHz repetition rate.
• Utilized a multiplex configuration with broadband mid-infrared pulses for rapid microspectrum acquisition (hundreds of milliseconds).
• Enabled switchable homodyne- and heterodyne-detection for self-phase-stabilized spectral interferometry.

Main Results:

• Successfully measured CH/CH2 stretching modes in biological samples like starch granules and collagen.
• Demonstrated the capability to probe the relationship between C-H modes and collagen triple-helix orientation.
• Achieved high-speed hyperspectral imaging with micron to submicron lateral resolution.

Conclusions:

• The developed multiplex VR SFG microscope operating at a high repetition rate is a powerful tool for detailed structural and spatial analysis of biological systems.
• This advancement broadens the applications of VR SFG microscopy for molecular-level investigations.