CANUNDA-AXICON generates nanoscale surface structuring using a Bessel beam

Copper shape groove drilling…

> Copper

> 323nm

> 6µJ / pulse

… with a reflective Bessel beam

in the processing plane:

> 400:1 aspect ratio
> 0.51 µm FWHM
> No oscillations over the propagation

Bessel profile x2 closer to theory

The partner

Fraunhofer Institute for Laser Technology (ILT) is a German research institute that focuses on technology transfer to industry, in particular by developing new laser sources and photonic components for various processes including cutting, surface treatment and micro-manufacturing.

The application

Surface structuring makes it possible to modify the properties of a surface by engraving a sub-micrometric or nanometric texture on it.

A Bessel beam has a far superior depth of field than a conventional Gaussian beam, making it particularly interesting for structuring rough or irregular surfaces or if machine precision is low.

The problem

Bessel beams can achieve depths of field of the order of a millimeter with a spot diameter of less than 1 µm and are generally generated using axicons.

However, conventional axicons have manufacturing defects, especially at the tip, which cause oscillations in the intensity profile along the propagation axis and limit process quality and stability.

The CANUNDA-AXICON solution

CANUNDA-AXICON makes it possible to generate a Bessel beam without oscillations and with an optimal depth of field. Thanks to its 100% reflective design, the beam properties are far superior to the refractive design of conventional axicons: no chromatic dispersion, stable pulse duration. The axicon is easily integrated in an industrial environment and can manage high power ultra-short-pulsed lasers with stability.