Microgrinding of lensed fibers by means of a scanning-probe microscope setup.

We describe a precision grinding procedure that allows treating a previously etched fiber tip to conform to predefined shapes, including hemispherical and axial conical (axicon) lenses. The grinding method is based on mechanical polishing with the fiber tip moving in a translational mode inside a conical polishing surface. The grinding procedure is performed in a homemade scanning probe microscope equipped with a shear-force sensor based on a piezoelectric tuning fork as well as with capacitor position sensors. The scanning probe microscope is operated either as atomic force microscope for topographic characterization of the tip shape and the polishing surface or as a scanning near-field microscope for measurement of the light focusing properties of the ground microlenses.