Analytical model of excimer laser homogenizer using dual-microlens arrays

Excimer lasers are widely used in advanced lithography, while the anisotropic intensity distribution and spatial coherence of these sources have not been simultaneously fully incorporated in homogenizer designs. To address this issue, we propose a tunable excimer laser model based on a partially coherent flattened Gaussian beam that accurately reflects the characteristics of practical light sources. Furthermore, by combining pseudo-mode representation with the angular spectrum method, we efficiently compute the transmission of partially coherent beams through homogenizers and systematically investigate the effects of coherence length, Fresnel number, and defocusing on their performance to achieve highly uniform output beams. Finally, the accuracy and reliability of the proposed excimer laser source and homogenizer model are experimentally verified.