Development of a nonlinear fiber-optic spectrometer for human lung tissue exploration

Area of Science:

• Biomedical Optics
• Materials Science
• Pulmonology

Background:

• Lung pathologies involve extracellular matrix (ECM) changes, particularly in collagen and elastin.
• Nonlinear optical techniques offer high specificity for analyzing ECM components.

Purpose of the Study:

• To develop a fiber-optic spectrometer for endoscopic nonlinear spectroscopy of lung ECM.
• To record second-harmonic generation (SHG) of collagen and two-photon excited fluorescence (2PEF) of collagen and elastin.

Main Methods:

• Development of a nonlinear fiber-optic spectrometer with dispersion compensation.
• Tunable excitation wavelength (790-900 nm) and short laser pulses (~70 fs).
• Investigation of SHG and 2PEF spectra from ex vivo human lung tissue, collagen, and elastin samples.

Main Results:

• The spectrometer successfully recorded SHG and 2PEF signals from lung ECM components.
• Excitation wavelength dependence of SHG and 2PEF spectra was analyzed.
• Results were validated against reference samples and standard nonlinear microspectroscopy.

Conclusions:

• The developed spectrometer enables tunable nonlinear spectroscopy of human lung ECM.
• This technology supports advanced endoscopic imaging based on collagen SHG and elastin 2PEF.
• Opens possibilities for tunable excitation nonlinear endomicroscopy.