Beam Shaping of High Power Multimode Lasers by Multi-Spot OpticsVisa övriga samt affilieringar
2024 (Engelska)Ingår i: Laser + Photonics for Advanced Manufacturing / [ed] Francois Courvoisier; Sylvain Lecler; Wilhelm Pfleging, SPIE - The International Society for Optics and Photonics, 2024, artikel-id 1300507Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]
Significant performance improvement of modern laser technologies such as welding, additive manufacturing, brazing, cladding, sheet metal cutting, based on the use of multi-kW multimode fiber lasers, fiber-coupled solid-state and diode lasers, can be improved using beam shaping optics providing optimal energy distribution by splitting the laser beam into several beamlets creating by further focusing separate multiple spots in the working plane and variable sharing energy between these spots. Various multi-spot patterns, such as square, line, rhombus, consisting of 4 or 9 separate spots, allow eliminating or reducing spatter, realizing optimum temperature distribution in the melt pool and stabilizing the processes in welding of tailored blanks, copper and aluminium parts in the production of batteries, zinc coated steel, cladding. Multimode lasers are characterized by low spatial coherence (large BPP or M2 values), therefore the most reliable optical approach to control the intensity distribution is imaging the fiber end with a collimator and a focusing objective. The proposed multi-spot beam shaping method presents a combination of fiber end imaging and geometrical separation of focused spots perpendicular to the optical axis, thus creating a compound working spot, called as quattroXX-spot or peaXXus-spot, as a combination of several spots. Varying the energy portions in separate spots and the distances between them make it possible to optimize for a particular application common intensity distribution of the compound spot. To ensure reliable operation with multi-kW lasers and to avoid optics damage the multi-focus optical devices are designed as refractive elements with smooth optical surfaces made of optical materials self-compensating thermo-optical effects that provides insignificant thermal lensing and, hence, negligible thermal focus shift and spherical aberration. The paper presents the proposed multi-spot optics, shows intensity profile measurements and application results.
Ort, förlag, år, upplaga, sidor
SPIE - The International Society for Optics and Photonics, 2024. artikel-id 1300507
Serie
Proceedings of SPIE, E-ISSN 0277-786X ; 13005
Nyckelord [en]
laser beam shaping, multi-spot optics, multi-kW multimode laser, welding, battery manufacture, additive manufacturing, cladding, brazing
Nationell ämneskategori
Bearbetnings-, yt- och fogningsteknik Atom- och molekylfysik och optik
Forskningsämne
Produktionsutveckling
Identifikatorer
URN: urn:nbn:se:ltu:diva-108572DOI: 10.1117/12.3014674ISI: 001269145200006Scopus ID: 2-s2.0-85198921095OAI: oai:DiVA.org:ltu-108572DiVA, id: diva2:1888602
Konferens
SPIE Photonics Europe [Laser + Photonics for Advanced Manufacturing 2024], Strasbourg, France, April 7-12, 2024
Anmärkning
Funder: Vetenskapsrådet (2020-04250); SAMOA – Sustainable Al additive Manufacturing fOr high performance Applications (18079);
ISBN for host publication: 9781510673298;
2024-08-132024-08-132024-11-20Bibliografiskt granskad