Fiber microaxicons fabricated by a polishing technique for the generation of Bessel-like beams

Thierry Grosjean,Daniel Charraut,Miguel Angel Suarez,Vincent Piquerey,Said Sadat Saleh,Patrick Sandoz,Idriss Abdoulkader Ibrahim

doi:10.1364/ao.46.008061

Abstract

We report a simple method for generating microaxicons at the extremity of commercial optical fibers. The proposed solution, based on a polishing technique, can readily produce any desired microaxicon cone angle and is independent of the nature of the fiber. An optical study of microaxicon performance, in terms of confinement ability and length of the generated Bessel-like beams, is presented as a function of the microaxicon angle. This study, made possible by the experimental acquisition of the 3D light distribution of the Bessel-like beams, reveals the relationship between the Bessel-like beam confinement zone and the beam length. Finally, the effect of diffraction of the Bessel-like beams, induced by the limited lateral extent of the incident fiber mode, is studied and discussed.

Highlights

For 20 years, Bessel beams [1,2] have drawn increasing interest in various domains such as optical acceleration [3,4], particle guiding [5] and manipulation [6,7], nonlinear optics [8 –14], optical interconnection and alignment [15,16], imaging [17], microfabrication [18], and lithography [19]
Since such a fiber microaxicon (FIMAX) is centered with respect to the core axis, the use of this component is straightforward: No adjustments of the system are required before use
Four polished FIMAXs of cone angles around 105°, 120°, 135°, and 150° ͑Ϯ2°͒ have been engineered at one of the two extremities of four pieces of the same type of optical fiber

Summary

Introduction

For 20 years, Bessel beams [1,2] have drawn increasing interest in various domains such as optical acceleration [3,4], particle guiding [5] and manipulation [6,7], nonlinear optics [8 –14], optical interconnection and alignment [15,16], imaging [17], microfabrication [18], and lithography [19]. The integration of microaxicons at the extremity of optical fibers offers the possibility of producing Bessel-like beams with a compact system that is easy to manipulate Since such a fiber microaxicon (FIMAX) is centered with respect to the core axis, the use of this component is straightforward: No adjustments of the system are required before use. The fiber is set smoothly in contact with the spinning disk by means of a highprecision translation stage (with a micrometer screw) in order to generate the conical microlens without damaging the fiber For this task, the micropositioning of the fiber is controlled with a binocular system to accurately detect the point where the fiber end is just at the level of the abrasive surface. The roughness level of the polished conical surface has to be sufficiently low and the cone summit sufficiently sharp to accurately generate Bessel beams These conditions are satisfied by using an abrasive disk with a diamond grain size of ϳ1 ␮m. The effects of machining artifacts on the final shape of the microcone lens (rounded summit, scratches and digs on the conical surface) are sufficiently weak that they do not disturb the generation of the Bessel-like beams

Bessel-like Beam 3D Imaging

Results

Conclusion