COHERENT improves coated glass cutting process using CANUNDA-AXICON Z-FLAT

Square holes drilling…

> Gorilla glass

> 1030nm

> HR coating

> 1mm glass

> 30µm coating

… with a homogeneous Bessel beam over the propagation axis

in the processing plane:
> 25µm FWHM
> 300mm length
> Transition length /3
> Homogeneity x1.5
> +50% useful energy

Removed Coated Width -20%

The partner

COHERENT is an American company and world leader in the supply of photonics solutions. As a manufacturer of laser-based technologies for scientific, commercial and industrial customers, the company provides solutions for a wide range of applications.

The application

Thin film ablation is the selective ablation of one or more layers from a multi-material substrate. This process is usually performed with ultrashort, often femtosecond lasers.

The problem

Customers who have coated glass want their glass cut ideally with no coating removed along the edge, or with minimum width removed.  If the coating is non-transparent to the laser then filamentation will not work. The method used by Coherent is to place the sample coated side down and perform filamentation through the uncoated transparent side.  The advantage is that it is a single-step process, but the problem is that the filamentation laser beam will ablate and damage the coating on the bottom side.

The CANUNDA-AXICON Z-FLAT solution

CANUNDA-AXICON Z-FLAT is a beam shaping module that can generate a custom Bessel beam. Based on Cailabs’ reflective axicon technology, it can handle high-energy femtosecond pulses with great stability, avoiding undesirable phenomena such as dispersion, chromatic aberrations and focus shift. It delivers a Bessel beam with a profile very close to the theoretical ideal, therefore with little oscillation.