Input polarization-independent polarization-sensitive optical coherence tomography using a depolarizer.

Area of Science:

• Biomedical Optics
• Medical Imaging
• Optical Engineering

Background:

• Polarization-sensitive optical coherence tomography (PS-OCT) is crucial for early disease diagnosis.
• Conventional PS-OCT systems require precise polarization control, making them susceptible to misalignment and signal instability.
• Instability arises from the sensitivity of polarization state to minor movements in optical fiber connections.

Purpose of the Study:

• To develop and demonstrate an input polarization-independent PS-OCT system.
• To overcome the limitations of conventional PS-OCT systems regarding polarization sensitivity and misalignment.
• To enhance the robustness and diagnostic accuracy of PS-OCT for clinical applications.

Main Methods:

• Introduction of a depolarizer into the PS-OCT system to achieve polarization independence.
• Characterization of optical power stability with arbitrary input polarization states.
• Validation using a quarter-wave plate to measure retardance and optical axis orientation.
• Imaging of biological samples, specifically the nail bed, to assess birefringent properties.

Main Results:

• The proposed system demonstrated significantly improved optical power stability (9% variation) compared to standard systems (84% variation) for arbitrary input polarization.
• Accurate measurements of retardance and optical axis orientation were achieved for a quarter-wave plate.
• Successful imaging of the birefringent properties of the nail bed was demonstrated.

Conclusions:

• The developed input polarization-independent PS-OCT system is robust and overcomes critical limitations of conventional designs.
• The system's stability and accuracy in measuring birefringence hold promise for improved diagnostic capabilities in clinical settings.
• This advancement is expected to enhance the early detection of pathological conditions through more reliable imaging.