Optical design of Schwarzschild microscope for plasma diagnostics

Based on the third order aberration theory, the optical system of an EUV Schwarzschild microscope is designed for laser plasma diagnostics. The microscope works at 18.2 nm with the numerical aperture of 0.1 and the magnification of 10. The optical system is optimized to achieve the spatial resolution of 0.3 μm in the center field and about 0.4 μm in the field of ±1 mm. The influences of Schwarzschild system tolerances are analyzed in the aspects of system assembly, alignment and components fabrication. The results show that the optics surface irregularity is the main factor affecting imaging resolution; by improving the accuracy of system alignment, the deterioration of resolution, resulting from imaging distance tolerance, and the spacing and the curvature radius tolerances of objectiv