Dark-field polarization-sensitive optical coherence tomography.

Area of Science:

• Biomedical optics
• Medical imaging technology
• Ophthalmology

Background:

• Polarization-sensitive optical coherence tomography (PS-OCT) provides structural and birefringent information.
• Conventional fiber-based PS-OCT struggles with specular reflections, causing signal saturation and hindering polarization measurements.
• Specular reflections are a significant challenge in PS-OCT imaging of various biological tissues.

Purpose of the Study:

• To develop and characterize a novel dark-field PS-OCT system.
• To mitigate the impact of specular reflections in PS-OCT imaging.
• To evaluate the performance of the dark-field PS-OCT compared to conventional methods.

Main Methods:

• Implementation of a dark-field PS-OCT system using Bessel-beam illumination and Gaussian-beam detection.
• Integration of a passive delay unit (PDU) for polarization-sensitive measurements.
• Comparative analysis of the new system against conventional Gaussian-beam based PS-OCT using polarization components and diverse samples, including human skin.

Main Results:

• The dark-field PS-OCT system successfully avoided specular reflection artifacts.
• Performance of the dark-field PS-OCT was comparable to conventional PS-OCT in terms of polarization components.
• The system demonstrated effective imaging on various samples, including human skin, without saturation issues.

Conclusions:

• The developed dark-field PS-OCT effectively overcomes the limitations of specular reflections.
• This technique offers a viable solution for PS-OCT applications where strong surface reflections are present.
• Dark-field PS-OCT shows promise for practical biomedical imaging scenarios with unavoidable specular reflections.