Damage threshold power during writing of widely spaced individual lines with IP-DIP photoresist. (a) Effect of writing speed on the damage threshold; (b) optical image of the writing process illustrating formation of bubbles at high laser power; and (c) optical image of the same region 3 s after writing. Damaged lines were identified by the presence of bubbles or discontinuity in the lines. Lines from left to right were written at the same speed but at progressively higher power. Scale bars are 20 μm long.