Improved sensitivity roll-off in dual reference, buffered spectral-domain optical coherence tomography.

SIGNIFICANCE

While spectral-domain optical coherence tomography (SD-OCT) is a preferred form of OCT imaging, sensitivity roll-off limits its applicability for certain biomedical imaging applications.

AIM

The aim of this work is to extend the imaging range of conventional SD-OCT systems for imaging large luminal organs such as the gastrointestinal tract.

APPROACH

We present an SD-OCT system operating at a center wavelength of 1300 nm that uses two delayed reference arms to reduce sensitivity roll-off and an optical switch and a fiber optic delay line to ensure that the interference spectra are acquired from the same sample time window.

RESULT

The proposed system was used to image swine colon ex vivo and duodenum in vivo, demonstrating improved image quality due to a ∼14  dB increase in sensitivity at the edges of the ranging depth.

CONCLUSION

The proposed system requires modest hardware implementation and is compatible with catheter-based endoscopic helical scanning with enhanced sensitivity for the samples at a distance of ∼6  mm from the zero delay point.