title: Ultrathin fiber probes with extended depth of focus for optical coherence tomography.
abstract: We report on a novel scheme for extending the depth of focus (DOF) of ultrathin (125 μm diameter) fiber probes for optical coherence tomography (OCT) using a simple phase mask consisting of graded-index (GRIN) fiber. The technique is compatible with existing all-in-fiber probe fabrication techniques, and our simulations show that it can provide a DOF gain of ~2 at a modest ~5 dB reduction of peak sensitivity. In a prototype device using commercially available GRIN fiber, a DOF gain of 1.55 is obtained, validated by beam profiling and OCT imaging.
authors.affiliation: Optical+Biomedical Engineering Laboratory, School of Electrical, Electronic & Computer Engineering, The University of Western Australia, WA 6009, Australia. dirk.lorenser@uwa.edu.au
authors.forename: Dirk
authors.initials: D
authors.lastname: Lorenser
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Yang
authors.forename: David D
authors.initials: DD
authors.lastname: Sampson
mesh_terms: D002957:Citrus / Q000166:cytology; D055100:Optical Fibers; D041623:Tomography, Optical Coherence / Q000295:instrumentation*