Figure 5From: Flower-like Na2O nanotip synthesis via femtosecond laser ablation of glass SEM images of glass substrates after ablation at a repetition rate of 25 MHz and dwell times (a) 2 ms, showing no nanotip formation; (b) 5 ms; and (c) 10 ms showing rare occurrences of flower-like nanotips. Back to article page