Potential pitfalls in the design of x-ray/EUV imaging systems

Recent advances in X-ray sources and optical fabrication techniques have resulted in a resurgence of activity in the field of X-ray and extreme ultraviolet (EUV) imaging systems. Novel approaches to the fabrication of grazing incidence X-ray mirrors and the rapidly emerging technology of enhanced reflectance X-ray multilayers are producing new advances in the areas of X-ray/EUV astronomy, soft X-ray microscopy. X-ray microlithography, and synchrotron source applications. However, traditional optical design and analysis techniques (geometrical ray tracing) are woefully inadequate for predicting the performance oi high resolution imaging systems at these very short wavelengths. The diffraction effects of highly obscured annular apertures (grazing incidence optics) and small angle scattering effects due to residual optical fabrication errors will frequently dominate geometrical design errors in the degradation of image quality. These and other potential pitfalls in the design and analysis of high-resolution X-ray/EUV imaging systems will be emphasized and illustrated by examples in current applications of major interest.