Multimodal nonlinear endomicroscopic imaging probe using a double-core double-clad fiber and focus-combining...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Microscopy

Background:

• Multimodal non-linear microscopy offers label-free tissue analysis.
• In vivo endoscopic applications require compact, robust, and synchronized laser delivery systems.
• Existing systems face challenges with fiber delivery, signal collection, and objective design.

Purpose of the Study:

• To develop an ultra-compact fiber-scanning endoscope for multimodal non-linear endomicroscopy.
• To enable routine medical applications of label-free in vivo tissue imaging.
• To overcome limitations of current endoscopic non-linear microscopy systems.

Main Methods:

• Integration of a compact four-wave mixing fiber laser with a custom-designed pure silica fiber.
• Utilized a 2.4 mm diameter, high numerical aperture endomicroscopic objective for efficient signal collection.
• Employed a linear diffractive optical grating and a distal resonant fiber scanner for synchronized laser delivery and imaging.

Main Results:

• Demonstrated diffraction-limited performance for tissue imaging at 1 frame per second.
• Achieved sub-micron spatial resolution with high transmission (65%) from laser to specimen.
• Enabled background-free, low-loss, high peak power laser delivery and efficient backward signal collection.

Conclusions:

• The developed fiber-scanning endoscope platform is suitable for multimodal non-linear endomicroscopy.
• This technology facilitates label-free in vivo tissue investigation with high resolution and speed.
• The system addresses key challenges for routine medical implementation of advanced microscopy techniques.