title: Refractive-index profiling of embedded microstructures in optical materials.
abstract: We describe use of a phase-sensitive low-coherence reflectometer to measure spatial variation of refractive index in optical materials. The described interferometric technique is demonstrated to be a valuable tool to profile the refractive index of optical elements such as integrated waveguides and photowritten optical microstructures. As an example, a refractive-index profile is mapped of a microstructure written in a microscope glass slide with an ultrashort-pulse laser.
authors.affiliation: Department of Electrical and Computer Engineering, University of Texas, Austin 78712, USA. dpdave@mail.utexas.edu
authors.forename: Digant P
authors.initials: DP
authors.lastname: Davé
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Milner