Stable fiber-based polarization-sensitive optical coherence tomography using polarization maintaining common-path...

Our work advances the development of fiber-based polarization-sensitive optical coherence tomography (PS-OCT) by stabilizing the output polarization state of the light beam when the system is under environmental disturbance. While the fiber-based PS-OCT has been demonstrated previously, it remains a challenge for the traditional fiber-based PS-OCT to obtain a stable measurement when the optic fibers are disturbed by the environment. This important issue is addressed, paving the path for clinical translation of PS-OCT, which can provide a unique perspective of the biological samples.

Polarization maintaining common-path (CP) interferometer is fabricated with the goal of providing a stable fiber-based PS-OCT imaging system that is only responsive to the polarization changes generated by the sample, immune to environmental conditions.

The system is implemented by incorporating a CP interferometer together with polarization maintaining (PM) fibers. The PM fibers are used to preserve the two orthogonal linearly polarized components of the light during propagation. By sharing the CP in the sample and reference arms, any variations in phase retardation can be eliminated between the two channels in the PM fibers. The combination of the PM fiber and the CP interferometer ensures the stability of the output polarization state.

The stability of the proposed PS-OCT system is tested when a periodically stressed disturbance is applied to the fibers within the system. Stable in vivo PS-OCT images of the mouse thigh are demonstrated.

We have demonstrated a stable fiber-based PS-OCT system that combined the PM fiber and the CP configuration together. We have shown that the output polarization states and the system sensitivity can keep stable over time under the environmental disturbances to the system.