En-face time-domain optical coherence tomography with dynamic focus for high-resolution imaging

Area of Science:

• Biomedical Optics
• Medical Imaging
• Ophthalmology

Background:

• Optical coherence tomography (OCT) enables microstructure imaging in translucent samples.
• Standard OCT techniques face limitations in maintaining resolution over extended imaging depths.
• Dynamic focus (DF) offers a potential solution to improve axial resolution in OCT.

Purpose of the Study:

• To implement and evaluate a dynamic focus optical coherence tomography (DF-OCT) system.
• To assess the capability of DF-OCT for imaging microstructures in various translucent biological samples.
• To compare the imaging performance of DF-OCT with conventional OCT.

Main Methods:

• A time-domain OCT system operating at 1300 nm was adapted for dynamic focus.
• The dynamic focus procedure involved synchronizing the confocal gate with depth scanning.
• A confocal gate of 180 µm was utilized to achieve consistent transversal resolution.
• Imaging was performed on a phantom, human skin, teeth, and larynx, with and without DF.

Main Results:

• The implemented DF-OCT system demonstrated effective microstructure imaging.
• Consistent transversal resolution was maintained over a larger axial range compared to conventional OCT.
• DF-OCT provided improved imaging of biological samples, including skin, teeth, and larynx.
• Visual comparison showed enhanced details in samples imaged with DF-OCT.

Conclusions:

• Dynamic focus optical coherence tomography (DF-OCT) is a viable technique for enhanced imaging of translucent samples.
• DF-OCT offers improved and consistent resolution across extended depths, surpassing conventional OCT.
• The developed DF-OCT system shows promise for various biomedical imaging applications.