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The growing use of carbon-fibre-reinforced polymer (CFRP) composites as high-performance lightweight materials in aerospace and automotive industries demands efficient and low-cost machining technologies. The use of laser machining for cutting and drilling composites is attractive owing to its high speed, flexibility, and ease of automation. However, the anisotropic material properties of composites, and issues related to the heat-affected zone (HAZ), charring, and potential delamination during laser processing, are major obstacles in its industrial applications. In order to improve the quality and dimensional accuracy of CFRP laser machining, it is important to understand the mechanism of the transient thermal behaviour and its effect on material removal. Based on the ‘element death’ technique of the finite element (FE) method, a three-dimensional model for simulating the transient temperature field and subsequent material removal has been developed, for the first time, on a heterogeneous fibre—matrix mesh. In addition to the transient temperature field, the model also predicts the dimensions of the HAZ during the laser machining process. Experimental results obtained with same process variables using a 355 nm DPSS Nd:YVO4 laser were used to validate the model. Based on the investigation, the mechanism of material removal in laser composite machining is proposed. The results suggest that the employed FE approach can be used to simulate pulsed laser cutting of fibre-reinforced polymer composites.

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Nanofabrication by using lasers with a spatial resolution beyond the optical diffraction limit is a challenging task. One of the solutions is to use near-field techniques, in which evanescent waves dominate over free waves in the vicinity of scattering objects and sub-diffraction-limited focus (as small as ∼10 nm) can be achieved. Theoretical modelling of near-field phenomena is extremely important for the understanding of these near-field techniques, especially for some cases where it is not possible to directly measure the near-fields. In this article, a brief review of the existing near-field laser nanofabrication techniques is given. Different theoretical methods for the computation of optical near-fields, including both analytical and numerical methods, are then presented. The optical near-field distributions of different micro/nano-systems (isolated particles, aggregated particles, particles on the substrate, particles in liquid, and the tip-sample system) are then reviewed in detail within the framework of laser nanofabrication.

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