Nearly diffraction-limited focusing of a fiber axicon microlens

We report a simple method of generating nearly diffraction-limited focused spot with a fiber axicon microlens. It is fabricated at the end of a commercially available single-mode optical fiber by the selective chemical etching method that allows fine control of the cone angle of the fiber. The walking distance of the microlens is estimated to be $\text{∼1\hspace{0.5em}μ}\mathrm{m},$ which is measured by the photoluminescence from semiconductor single quantum dots.