Mapping of surface refractive-index distribution by reflection SNOM

Ilya Radko, Valentyn S. Volkov, Sergey I. Bozhevolnyi, Jes Henningsen, Jens Pedersen

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review


Scanning near-field optical microscopy (SNOM) in reflection is employed for high-resolution mapping of surface refractive-index distributions. Two different single-mode optical fibers with step-index profiles are characterized using a reflection SNOM setup, in which cross-polarized detection is employed to increase the contrast in optical images and, thereby, the method sensitivity. The SNOM images exhibit a clear ring-shaped structure associated with the fiber stepindex profile, indicating that surface refractive-index variations being smaller than 10-2 can be detected. It is found that the quantitative interpretation of SNOM images requires accurate characterization of a fiber tip used, because the detected optical signal is a result of interference between the optical fields reflected by the sample surface and by the fiber tip itself. The possibilities and limitations of this experimental technique are discussed.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Original languageEnglish
Title of host publicationProceedings SPIE
Number of pages7
PublisherSPIE - International Society for Optical Engineering
Publication date2005
Publication statusPublished - 2005
Externally publishedYes
EventNano- and Micro-Metrology -
Duration: 24. Aug 2010 → …


ConferenceNano- and Micro-Metrology
Period24/08/2010 → …


Dive into the research topics of 'Mapping of surface refractive-index distribution by reflection SNOM'. Together they form a unique fingerprint.

Cite this