Physical compensation method for dispersion of multiple materials in swept source optical coherence tomography

Area of Science:

• Ophthalmic imaging
• Optical coherence tomography
• Biomedical optics

Background:

• High-speed swept source-optical coherence tomography (SS-OCT) systems are crucial for ophthalmic diagnostics.
• Dispersion in optical components, particularly glass materials in the sample arm, severely degrades imaging quality in SS-OCT.
• Existing methods may not sufficiently address dispersion challenges in high-speed systems.

Purpose of the Study:

• To develop and implement a physical dispersion compensation method for a 1060 nm SS-OCT system.
• To enhance imaging performance, including depth, signal-to-noise ratio, and axial resolution.
• To demonstrate the effectiveness of the method through model eye and in vivo human retinal imaging.

Main Methods:

• Construction of a 100 KHz scanning rate SS-OCT system operating at 1060 nm.
• Second-order dispersion simulation analysis for various materials.
• Implementation of physical compensation methods to achieve dispersion equilibrium.
• Performance evaluation using model eye experiments and in vivo human retinal imaging.

Main Results:

• Achieved an imaging depth of 4.013 mm in air after dispersion compensation.
• Enhanced signal-to-noise ratio by 11.6% to 53.8 dB.
• Improved axial resolution by 19.8% to 7.7 μm, approaching the theoretical limit.
• Obtained structurally distinguishable images of the human retina.

Conclusions:

• The proposed physical dispersion compensation method effectively enhances imaging performance in SS-OCT systems.
• This technique enables better visualization of low scattering mediums, such as the human retina.
• The method offers a practical solution for overcoming dispersion-induced artifacts in high-speed ophthalmic OCT.