AbstractThe direct use of diode lasers for cutting sheet metal has high potential to decrease operational costs, but, currently, implementation in industrial environments is constrained by beam quality. In this paper the performance of a novel direct diode laser (DDL) with increased beam quality is documented for both fusion and flame cutting and compared to conventional CO2 and fiber laser sources. Experimental tests were carried out for steel and aluminium based on a Design of Experiments approach. Furthermore, an analytical model, focusing on the absorption of lasers in metals, is described here, which predicts and clarifies performance variation. Although the observed laser beam quality is still lower than the other studied technologies, industrially relevant cutting speeds, with acceptable surface quality, are achievable with DDL, as validated by our results