No abstract

No abstract

Due to their high speed and versatility, laser processing systems are now commonplace in many industrial production lines. However, as the need to reduce the environmental impact from the manufacturing industry becomes more urgent, there is the opportunity to evaluate laser processing systems to identify opportunities to improve energy efficiencies and thus reduce their carbon footprint. While other researchers have studied laser processing, the majority of previous work on laser systems has focused on the beam–material interaction, overlooking the whole system viewpoint and the significance of support equipment. In this work, a methodical approach is taken to design a set of energy modelling terminologies and develop a structured power metering system for laser systems. A 300 W fibre laser welding system is used to demonstrate the application of the power characterization system by utilizing a purpose-built power meter. The laser is broken down according to sub-system, with each part analysed separately to give a complete overall power analysis, including all auxiliary units. The results show that the greatest opportunities for efficiency improvements lie in the auxiliary units that support the laser devices as these were responsible for a majority of the electrical draw; 63.1% when the laser was operated at 240 W, and increasing as the beam power reduced. The remaining power draw was largely apportioned to electrical supply inefficiencies. In this work, the laser device delivered a maximum of 6% of the total system power. The implications of these results on laser processing system design are then discussed as is the suitability of the characterization process for use by industry on a range of specific laser processing systems.

Within the family of thin-film photovoltaics (PV), cadmium telluride has the fastest growing market share due to its high efficiencies and low cost. However, as with other PV technologies, the energy required to manufacture the panels is excessive, encompassing high environmental impact and manufacturing energy payback times of the order of 2-3 years. As part of the manufacturing process, the panels are annealed at temperatures of approximately 400 °C for 30 min, which is inherently inefficient. Laser heating has previously been investigated as an alternative process for thin-film annealing, due to its advantages with regard to its ability to localize heat treatment, anneal selectively, and its short processing time. In this investigation, results focusing on improvements to the laser-based annealing process, designed to mitigate panel damage by excessive thermal gradients, are presented. Simulations of various laser beam profiles are created in COMSOL and used to demonstrate the benefit of laser beam shaping for thin-film annealing processes. An enabling technology for this, the holographic optical element, is then used to experimentally demonstrate the redistribution of laser beam energy into an optimal profile for annealing, eliminating thermal concentrations.

No abstract