A method for enhancing the photoluminescence of silicon nanocrystals in a silicon oxide matrix by fabrication of periodic surface structures through laser irradiation is demonstrated. ArF excimer lasers are used to produce periodic line structures by material ablation. Photoluminescence, Raman, and transmission electron microscope measurements consistently show the formation of crystalline silicon after high-temperature annealing. A 2.6-fold enhancement of photoluminescence signal is measured for a periodic line structure with 600 nm period. The influence of a surface structure on the photoluminescence from the silicon oxide layer is discussed in terms of a simple model describing the main effect.