Enlarged Near-Field Optical Imaging

Millimeter scale near-field optical microscopy is here reported. It is demonstrated in the near infrared by observing light propagating in an integrated glass waveguide. Enlarged near-field imaging was made possible thanks to the use of a homemade interferometric translation stage with nanometric scale repeatabilities combined with a commercial atomic force microscope. An integrated optical component was used as a representative example of multiscale components requiring large scale highly resolved optical mapping. By imaging stationary waves on a millimeter long range followed by Fourier analysis, an uncertainty of a few 10(-4) on the waveguide modes effective index was obtained. While improving the optogeometrical parameter retrieval precision, millimeter scans make the technique sensitive to properties such as birefringence. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3200953]