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.
© 2002 Optical Society of America
(220.4000) Optical design and fabrication : Microstructure fabrication
(220.4840) Optical design and fabrication : Testing
(290.3030) Scattering : Index measurements
(320.7160) Ultrafast optics : Ultrafast technology
Digant P. Dav and Thomas E. Milner, "Refractive-Index Profiling of Embedded Microstructures in Optical Materials," Appl. Opt. 41, 2038-2042 (2002)