Dual-line fabrication method in direct laser lithography to reduce the manufacturing time of diffractive optics elements.

To reduce the manufacturing time of DOEs (Diffractive Optics Elements) and POEs (Periodical Optics Elements), a new fabrication method in direct laser lithography is proposed based on the laser ablation phenomenon and the thermochemical effect of chrome. The basic mechanism of the proposed method and experimental results are also presented. It was found that when a 3 × 3 rectangular pattern is fabricated, the proposed method can reduce the total lithographic length by approximately 33%. The manufacturing time is reduced by nearly 52%. When fabricating a 1,000 × 1,000 rectangular pattern, the manufacturing time was reduced by more than 90%. The time reduction rate is drastically improved when the number of patterns is increased. Various patterns including rectangular, triangular, parallelogram, and diamond shape were fabricated by using the proposed method.