Line-field confocal optical coherence tomography based on tandem interferometry with a focus-tunable lens

Area of Science:

• Biomedical Optics
• Optical Imaging
• Microscopy

Background:

• Conventional optical coherence tomography (OCT) systems face limitations in imaging speed and depth.
• Line-field confocal OCT (LC-OCT) offers improved resolution but requires advancements for dynamic focusing and extended imaging.
• Tandem interferometry provides a robust framework for high-resolution optical measurements.

Purpose of the Study:

• To introduce and characterize an innovative LC-OCT system utilizing tandem interferometry and a focus-tunable lens.
• To demonstrate dynamic focusing capabilities for enhanced imaging depth and speed.
• To evaluate the system's performance in resolving microstructures within biological samples.

Main Methods:

• Development of an LC-OCT system integrating tandem interferometry with a focus-tunable lens for dynamic focusing.
• Coupling a Linnik-type imaging interferometer with a Michelson-type compensating interferometer for coherence plane scanning.
• Utilizing a piezoelectric linear translation stage for precise scanning control.

Main Results:

• Achieved axial and lateral resolutions of approximately 1 µm over a 400 µm imaging depth.
• Acquired vertical section images (B-scans) of skin at 14.3 fps, resolving epidermal and dermal structures.
• Obtained images of a tissue phantom with an imaging depth exceeding 1.4 mm through refocusing and stitching.

Conclusions:

• The developed LC-OCT system offers high resolution and dynamic focusing capabilities.
• The system demonstrates potential for miniaturization, increased imaging speed, and extended imaging depth in OCT.
• This technology holds promise for advanced in vivo and ex vivo tissue imaging applications.