Gas-Cell Referenced Swept Source Phase Sensitive Optical Coherence Tomography

Distinct reference and signal interferometers in combination with a gas-cell spectral reference are employed to increase sensitivity and environmental stability of a swept source phase-sensitive optical coherence tomography. A displacement sensitivity (DS) of 65 pm at 280-μm depth and DS degradation with depth of 0.0015 rad/mm is achieved. Differential DS of 234 pm in a 127-μm -thick scattering phantom is six-fold superior to previously reported values. DS degradation with a depth of 0.026 rad/mm is reported for tissue-like scattering phantoms. Measured depth-dependent DS suggests that digitization time jitter noise contributes to degradation of phase sensitivity with depth.