Nearly degenerate two-color impulsive coherent Raman hyperspectral imaging.

Area of Science:

• Spectroscopy and vibrational analysis
• Ultrafast laser applications
• Hyperspectral imaging techniques

Background:

• Impulsive stimulated Raman scattering (ISRS) is valuable for low-frequency Raman vibrational modes (<300 cm⁻¹).
• A key challenge for ISRS is its translation into an effective imaging modality.
• Separating pump and probe pulses is a significant hurdle in ISRS applications.

Purpose of the Study:

• To introduce and demonstrate a simplified strategy for ISRS spectroscopy and hyperspectral imaging.
• To overcome the challenge of pump-probe pulse separation in ISRS.
• To enable ISRS microscopy using a single-color ultrafast laser source.

Main Methods:

• Utilized complementary steep edge spectral filters for probe beam separation.
• Implemented a single-color ultrafast laser source for ISRS microscopy.
• Achieved separation of the probe beam detection from the pump beam.

Main Results:

• Successfully obtained ISRS spectra covering low-frequency vibrational modes (<50 cm⁻¹).
• Demonstrated the capability for hyperspectral imaging using the developed ISRS method.
• Showcased polarization-dependent Raman spectra acquisition.

Conclusions:

• The developed strategy offers a simple and effective approach for ISRS spectroscopy and hyperspectral imaging.
• This method facilitates ISRS microscopy with a single laser, overcoming previous limitations.
• The technique successfully probes low-frequency vibrational modes and enables advanced imaging capabilities.