High-resolution optical coherence tomography over a large depth range with an axicon lens

Zhihua Ding,J Stuart Nelson,Yonghua Zhao,Zhongping Chen,Hongwu Ren

doi:10.1364/ol.27.000243

Abstract

In optical coherence tomography, axial and lateral resolutions are determined by the source coherence length and the numerical aperture of the sampling lens, respectively. Whereas axial resolution can be improved by use of a broadband light source, there is a trade-off between lateral resolution and focusing depth when conventional optical elements are used. We report on the incorporation of an axicon lens into the sample arm of an interferometer to overcome this limitation. Using an axicon lens with a top angle of 160 degrees , we maintained 10-microm or better lateral resolution over a focusing depth of at least 6 mm. In addition to having high lateral resolution, the focusing spot has an intensity that is approximately constant over a greater depth range than when a conventional lens is used.

Highlights

Three-dimensional high-resolution optical imaging has potential clinical applications in the emerging field of biomedical optics
Whereas axial resolution can be improved by use of a broadband light source,[3,4] there is a trade-off between lateral resolution and focusing depth when conventional optical elements are used, because a beam cannot be produced that has simultaneously a long focal depth and a narrow lateral width
Schematic of the sample arm of the Optical coherence tomography (OCT) system with an axicon lens to achieve simultaneous high lateral resolution and greater depth of focus: a, angle formed by the conical surface with the f lat surface of the axicon lens; b, intersection angle of the geometrical rays with the optical axis; Rz, radius of the incident beam; D, waist of the incident beam; L, depth of focus

Summary

Introduction

Three-dimensional high-resolution optical imaging has potential clinical applications in the emerging field of biomedical optics. Title High-resolution optical coherence tomography over a large depth range with an axicon lens. High-resolution optical coherence tomography over a large depth range with an axicon lens

Results

Conclusion