In vitro 3D anterior segment imaging in lamb eye with extended depth range swept source optical coherence tomography

•A complex conjugate free long depth range swept source optical coherence tomography system is demonstrated.•The system relies on “coherence revival” principle and uses an external cavity tunable laser.•The sensitivity fall-off for system is faster for “0” cavity offset than “+1”.•The SSOCT system has depth range of 10.5 mm and axial resolution of 8.5 μm in air.•In vitro 2D B-scans, C-scans and 3D imaging of full anterior segment of lamb eye are reported.

A complex conjugate resolved, extended depth range, high speed 1 μm swept-source optical coherence tomography (SSOCT) provides a dense three-dimensional (3-D) imaging of the entire anterior segment of eye. SSOCT system utilizes “coherence revival” characteristics of the light source (external cavity tunable laser, ECTL), which is automatically phase modulated. We describe implementation of this with a common swept laser with built-in k-clock to allow imaging in high depth range, 10.5 mm in air, without any external MZI clock. The system is capable of generating long depth range without any modulators or frequency shifter. Most of the commercially available OCT systems are limited with this type of application due to low acquisition speed, resolution, and axial imaging range. The sensitivity fall-off profiles for extended imaging depth range were also presented with matched and mismatched interferometer optical path delays. The imaging feasibility of this system is demonstrated by in vitro 3D imaging of the full anterior segment of lamb eye.