Instantaneous quadrature low-coherence interferometry with 3×3 fiber-optic couplers

Instantaneous quadrature low-coherence interferometry with 3 x 3 fiber-optic couplers.

We describe fiber-based quadrature low-coherence interferometers that exploit the inherent phase shifts of 3 x 3 and higher-order fiber-optic couplers. We present a framework based on conservation of energy to account for the interferometric shifts in 3 x 3 interferometers, and we demonstrate that the resulting interferometers provide the entire complex interferometric signal instantaneously in...

Miniature fiber-optic force sensor based on low-coherence Fabry-Pérot interferometry for vitreoretinal microsurgery

During vitreoretinal surgery, the surgeon manipulates retinal tissue with tool-to-tissue interaction forces below the human sensory threshold. A force sensor (FS) integrated with conventional surgical tools may significantly improve the surgery outcome by providing tactile feedback to the surgeon. We designed and built a surgical tool integrated with a miniature FS with an outer diameter smalle...

Gradient-index fiber-optic microprobes for minimally invasive in vivo low-coherence interferometry.

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 M...

Fiber Optic Interferometry Training Kit

Frequency-Shifted Interferometry for Fiber-Optic Sensing

Frequency-Shifted Interferometry for Fiber-Optic Sensing Fei Ye Doctor of Philosophy Graduate Department of Electrical and Computer Engineering University of Toronto 2013 This thesis studies frequency-shifted interferometry (FSI), a useful and versatile technique for fiber-optic sensing. I first present FSI theory by describing practical FSI configurations and discussing the parameters that aff...