Compact and accurate concept of laser wavemeters based on ellipsometry.

Common laser wavemeters are based on a scanning Michelson interferometer. Displacements of the moving mirror as long as tens of centimeters are needed to reach a relative accuracy of 1 × 10(-6) (1σ) on the unknown laser wavelengths. Such a long displacement range makes the system very sensitive to mechanical vibrations and to misalignments of the laser beams. The purpose of this paper is to demonstrate a new concept of laser wavemeter based on the measurements of the ellipsometric parameters ψ and Δ of the laser beams. Experimental results show that a 10(-6) (1σ) accuracy level could be reach with a displacement range of only 4 µm. Implementations of the device are described. Comparisons between our polarimetric wavemeter and a calibrated wavemeter are presented for two lasers, an extended cavity laser diode at 656 nm and a 532 nm green line Nd:YAG laser.

Note: Multiscale scanning probe microscopy.

Combining the nanoscopic and macroscopic worlds is a serious challenge common to numerous scientific fields, from physics to biology. In this paper, we demonstrate nanometric resolution over a millimeter range by means of atomic-force microscopy using metrological stage. Nanometric repeatability and millimeter range open up the possibility of probing components and materials combining multiscale properties i.e., engineered nanomaterials. Multiscale probing is not limited to atomic-force microscopy and can be extended to any type of scanning probe technique in nanotechnology, including piezoforce microscopy, electrostatic-force microscopy, and scanning near-field optical microscopy.

Enlarged atomic force microscopy scanning scope: novel sample-holder device with millimeter range.

We propose a homemade sample-holder unit used for nanopositionning in two dimensions with a millimeter traveling range. For each displacement axis, the system includes a long range traveling stage and a piezoelectric actuator for accurate positioning. Specific electronics is integrated according to metrological considerations, enhancing the repeatability performances. The aim of this work is to demonstrate that near-field microscopy at the scale of a chip is possible. For this we chose to characterize highly integrated optical structures. For this purpose, the sample holder was integrated into an atomic force microscope. A millimeter scale topographical image demonstrates the overall performances of the combined system.