Axicon lens on optical fiber forming optical tweezers, made by focused ion beam milling

The purpose of this article is to show that it is possible to make efficient optical tweezers using a properly modified single mode fiber. By using a micro-lens, fabricated directly on the cleaved end of an optical fiber, by a focused ion beam milling process, efficient optical tweezers can be obtained. A 30 keV focused Ga+ ion beam is used to mill a continuous profile microstructure. An axicon with 10 mu m diameters and 5 pm high is fabricated, which permits the transformation of a Gaussian mode in a Bessel mode beam. This particular mode was used to form an optical trap. Measures of the propagation profile and of the trapping effect will be discussed. (c) 2006 Elsevier B.V. All rights reserved.