Nonlinear optical endoscope based on a compact two axes piezo scanner and a miniature objective lens

Area of Science:

• Biomedical Optics
• Optical Engineering
• Microscopy

Background:

• Advanced endoscopic imaging techniques are crucial for in vivo diagnosis.
• Nonlinear optical microscopy offers high resolution and specificity for biological samples.

Purpose of the Study:

• To develop and characterize a novel nonlinear optical endoscope for high-resolution cellular imaging.
• To evaluate the performance of the endoscope in terms of resolution, field-of-view, and detection efficiency.

Main Methods:

• Utilized a hollow core photonic crystal fiber for single-mode illumination delivery and a multimode fiber for signal collection.
• Employed femtosecond laser pulses at 800 nm for two-photon fluorescence excitation.
• Measured axial and lateral resolutions, field-of-view, and detection efficiency using an avalanche photodiode.

Main Results:

• Achieved axial resolution of 5.8 micrometers and lateral resolution of 0.6 micrometers.
• Demonstrated a maximal field-of-view of 420 microm x 420 microm.
• Showed superior detection efficiency with an avalanche photodiode compared to a photomultiplier tube.

Conclusions:

• The developed nonlinear optical endoscope effectively resolves cellular details.
• The system's performance indicates significant potential for future in vivo imaging and diagnosis.