Reduction in heat affected zone and recast layer in laser materials processing using a photon sieve lens

•Photon sieves focus to a smaller spot size for a given NA compared to refractive lenses, without sacrificing depth of focus.•Increased resolution results in reduced oxidation, heat affected zone, and recast layer in laser materials processing.•Thermal confinement has important implications for biomedical, materials processing, and spectroscopy applications.