Weilun Chao received his Ph.D. from the Electrical Engineering and Computer Science department at the University of California, Berkeley in 2005. After degree completion, he joined the Center for X-Ray Optics at the Lawrence Berkeley National Laboratory. As a staff scientist, he is interested in the advancement of x-ray/EUV diffractive optics capabilities and their applications, EUV lithography and electron beam lithography. He has been developing various nanofabrication processes with electron beam lithography and pushing the spatial resolution and efficiency of soft x-ray and EUV microscopy using Fresnel zone plates.