The temperature distribution inside the material is of prime importance in laser material processing. Optimization of laser processes requires control over this temperature distribution in order to achieve the desired outcomes by manipulating heating/cooling rates and thermal gradients. So far, most of the laser material processing has been carried out by using circular and rectangular beam geometries with variations in laser power, spot size, and scanning speed. However, variations in these parameters are often limited by other processing conditions and it is not always possible to change, e.g. the scanning speed or laser power. One possible method of varying the temperature distribution, and hence the heating/cooling rates and thermal gradients, is to modify the geometry of laser beams. It has been shown that non-conventional laser beam geometries can be effectively employed for laser processes such as surface heating, transformation hardening, forming, melting of metallic materials, and laser cutting. This article presents a review of non-conventional laser beam geometries that can be utilized to improve and/or optimize many laser material processes. Some examples of laser material processing that have been previously studied in detail are briefly discussed.
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