title: Gradient-index fiber-optic microprobes for minimally invasive in vivo low-coherence interferometry.
abstract: We describe the design, construction, and application of what are believed to be the smallest fiber-optic probes used to date during imaging or diagnosis involving low-coherence interferometry (LCI). The probes use novel fiber-optic gradient-index (GRIN) lenses fabricated by a recently developed modified chemical-vapor-deposition (MCVD) process that avoids on-axis aberrations commonly marring MCVD-fabricated GRIN substrate. Fusing GRIN fiber lenses onto single-mode fiber yields automatically aligned all-fiber probes that insert into tissue through hypodermic needles as small as 31-gauge (inner diameter, 127 mum). We demonstrate the use of such probes with LCI by measuring microscopic brain motions in vivo.
authors.forename: William A
authors.initials: WA
authors.lastname: Reed
authors.forename: Man F
authors.initials: MF
authors.lastname: Yan
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Schnitzer