Project: Development of a novel laser cutting technology platform based upon Diffractive Optical Elements for fiber laser cutting

Project goal:_x000D__x000D_The goal of the project is to establish a prototype setup for demonstrating advanced fiber laser cutting with intelligent laser beam patterns in the cut kerf based upon near diffraction limited high power fiber laser beam modified by a Diffractive Optical Element to create the desired laser beam pattern in the cut kerf. _x000D__x000D_Background:_x000D__x000D_Laser cutting is a widely accepted production technology. In 2007 approximately 4,000 advanced laser cutting systems were sold globally in the so called flat bed laser cutting market, where 2 dimensional parts are cut in different materials, mostly in steel, stainless steel and aluminium in materials thicknesses between 0.5 and 20 mm. This market segment is representing a world market for systems sales and service of around 2 Billion. Euro._x000D__x000D_The technology has matured through the last 30 years. The market for laser cutting has been totally dominated by CO2-lasers as cutting sources._x000D__x000D_Within the last few years a new and very promising high power laser source has entered the market: The fiber laser. This laser has the potential of outperforming the existing high power lasers in industrial applications._x000D__x000D_From an investment point of view this laser source has the potential of offering a very competitively cost of ownership compared to the classical laser sources. From a technical point of view, the fiber laser has superior focussing properties compared to the CO2-laser. In practice a fiber laser beam can be focussed to diameters of 1/10 of a CO2-laser beam. Furthermore the light from a fiber laser is not disturbed by plasma formation in a narrow keyhole or kerf, as the CO2-laser beam is._x000D__x000D_Several companies have tried to apply this new laser for cutting. The results of state-of-the-art fiber laser cutting are promising in terms of very high cutting rates. However, the cut qualities obtained at these cutting rates are not acceptable. This is due to the melt flow in the cut kerf, where high cutting rates can be obtained when the melt is flowing around the laser beam in the so called keyhole laser cutting._x000D__x000D_The invention_x000D__x000D_This project aims towards developing fiber laser cutting applying a special patented technique, where the laser light is delivered in a complex beam pattern down into the cut kerf._x000D__x000D_Hereby the melt flow will be controlled so that the high cutting rate capability of keyhole cutting is combined with an efficient melt removal from the cut kerf._x000D__x000D_The potential of this technique has been demonstrated in a proof-of-concept project._x000D__x000D_ _x000D_Potential of the invention_x000D__x000D_The potential of the invention is to fully utilize the potential of high power fiber lasers in industrial cutting._x000D__x000D_Three market segments can be addressed:_x000D_1. Flat bed laser cutting. This is the large existing market for cutting. Here the invention is foreseen to be able to outperform existing CO2-laser cutting as well as state-of-the-art fiber laser cutting due to its combination of cutting rates and cut qualities._x000D_2. Micro laser cutting. This is a smaller but growing market, where for example stent cutting is a large market segment. Here the invention has some possibilities of refining the cut quality and improving the cutting rates._x000D_3. Remote laser cutting. This is a new and interesting technique, where sheet metal can be cut without gas assistance as in classical laser cutting. Hereby it can be realized on flexible robotized setups where the cutting optics are placed remote from the workpiece and the laser beam pattern is scanned over the workpiece at high speed. The invention is very promising and might stand for the industrial break through of this technique. By tailoring the beam pattern carefully, an efficient one-pass remote cutting should be possible._x000D__x000D_Technical approach of the project._x000D__x000D_In the DOEFLAC project the technological solution will be based upon the forming of the desired laser beam pattern via a Diffractive Optical Element (DOE). This DOE transforms a single mode fiber laser beam from a high power fiber laser into the desired complex beam pattern in the cut kerf._x000D__x000D_The desired beam pattern is foreseen to be asymmetric. The exact design of the beam pattern will be the subject of comprehensive experimental work, and the DOE will be optimized in an iterative process._x000D__x000D_To bring this technology into contour cutting, special devices must be developed for beam pattern rotation at high speed and high precision. This will also be a part of the project._x000D__x000D_The project consortium._x000D__x000D_The project will involve world leading competencies within: _x000D_¿ ¿ laser beam transmission_x000D_¿ development of DOEs_x000D_¿ laser cutting RTD_x000D_¿ fiber laser cutting systems integration. _x000D_

Acronym	DOEFLAC (Reference Number: 5197)
Duration	01/04/2010 - 31/03/2014
Project Topic	The goal of the project is to develop a novel (patent pending) laser cutting technology with a unique potential in terms of productivity and quality by applying multibeam patterns into the cut kerf by focussing a high power fiber laser beam by means of Diffractive Optical Elements.
Project Results (after finalisation)	We have established a strong knowledge in-house on design and manufacturing of diffractive optical elements._x000D__x000D_We have established a unique development platform for our future RTD in laser beam patterning for high power laser applications, including laser cutting and welding._x000D_
Network	Eurostars
Call	Eurostars Cut-Off 3

Project partner

Number	Name	Role	Country
5	Campana Livio	Partner	Italy
5	FINSOMAC S.r.l.	Observer	Italy
5	IPU	Coordinator	Denmark
5	Laser Optical Engineering Ltd	Partner	United Kingdom
5	Optoskand AB	Partner	Sweden