| 摘要 |
The present technology relates generally to laser ablation, and more particularly pertains to a system and method for eliminating structure and edge roughness, which is produced during the laser ablation of a material. Ablation of materials using a femtosecond laser beam produces a fine scale periodic structure in the ablated region. The structure consists of residual (i.e. unablated material) and is always perpendicular to the polarization direction of the laser beam. By changing the polarization direction during the ablation process, the structure is averaged over many directions and thus eliminated. This eliminates structure and edge roughness in a material caused by the laser ablation of the material. The method is employed to the repairing of photomasks so as to cause the optical quality thereof to be improved.
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