Determination of local refractive index variations in thin films by heterodyne interferometric scanning near-field optical microscopy.
We report on a heterodyne interferometric scanning near-field optical microscope developed for characterizing, at the nanometric scale, refractive index variations in thin films. An optical lateral resolution of 80 nm (lambda/19) and a precision smaller than 10(-4) on the refractive index difference have been achieved. This setup is suitable for a wide set of thin films, ranging from periodic to heterogeneous samples, and turns out to be a very promising tool for determining the optical homogeneity of thin films developed for nanophotonics applications.
Diziain
Séverine
S
Département d'Optique, Institut FEMTO-ST, CNRS UMR6174, Université de Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France. severine.diziain@uni-jena.de
Merolla
Jean-Marc
JM
Spajer
Michel
M
Benvenuti
Giacomo
G
Dabirian
Ali
A
Kuzminykh
Yury
Y
Hoffmann
Patrik
P
Bernal
Maria-Pilar
MP