Non-scanning 2-D Laser Cutting of Polyimide by Using a Computer-Generated Hologram

Laser processing is an effective way for precisely and accurately removing a small region of materials without tool wear. Conventional laser processing, which has a limitation on the processing speed, is performed by scanning a single spot on a target material. For improving its speed, a high-power laser beam can be spatially distributed using a hologram to simultaneously process a two-dimensional area. This technique has been used in experiments such as drilling, patterning, etc. However, as far as we know, due to several difficulties, no experiments have been reported that apply the holographic technique to non-scanning cutting with a single hologram. In this research, we experimentally performed non-scanning 2-D laser cutting of a polyimide film by using a single computer-generated hologram (CGH) and a high-power laser of 120 W. To do this, we designed a CGH to reconstruct twelve lines in a 24 mm × 23 mm area. This was then fabricated with fused silica so that it would not be damaged by the high-power laser. This method makes possible the achievement of a high throughput in a material cutting process by utilizing a high-power laser efficiently.