Depth-encoded all-fiber swept source polarization sensitive OCT.

Area of Science:

• Biomedical Optics
• Medical Imaging Technology

Background:

• Conventional optical coherence tomography (OCT) provides intensity-based imaging.
• Polarization-sensitive OCT (PS-OCT) offers advanced capabilities, including depth-resolved tissue birefringence assessment.
• Existing PS-OCT systems often face complexity challenges, hindering clinical adoption.

Purpose of the Study:

• To present a simplified and robust all-fiber PS-OCT system.
• To demonstrate its versatility for both ophthalmic and catheter-based imaging applications.
• To facilitate easier clinical translation of PS-OCT technology.

Main Methods:

• Development of an all-fiber PS-OCT system utilizing swept-source technology and polarization depth-encoding.
• Implementation of polarization multiplexing via polarization-maintaining fiber.
• Employing fiber-based polarization beam splitters, polarization controllers for ambiguity removal, and a simplified post-processing algorithm for speckle reduction.
• Adaptation for ophthalmic imaging using optical clock frequency doubling and for catheter-based imaging with a MEMS-tunable VCSEL and high-speed catheter.

Main Results:

• Successful demonstration of a simple and robust all-fiber PS-OCT system.
• Achieved extended imaging range for ophthalmic applications and 200 kHz imaging for catheter-based applications.
• Validated system performance in various in vivo and ex vivo tissues, including human retina, finger, lip, swine esophagus, and cardiovascular structures.

Conclusions:

• The developed all-fiber PS-OCT system is simpler to implement and maintain than previous systems.
• Its robust design enhances its potential for wider clinical translation.
• The system effectively assesses tissue birefringence, offering valuable diagnostic information.