Focusing multiple high-order harmonics in the extreme-ultraviolet and soft-x-ray regions by a platinum-coated ellipsoidal mirror

The focusability of multiple high-order harmonics in the extreme-ultraviolet and soft-x-ray regions is described, together with the design and performance of the ellipsoidal mirror used for this purpose. The mirror focuses intense coherent light in the spectral-region from 25 to 40 nm into a 2.4 mu m spot size with a focused peak intensity of 6 X 10(13) W/cm(2). The focal images indicate that a good beam profile is obtained with a near-Gaussian distribution and a beam quality factor (M-2 value) as low as 2.4. (c) 2006 Optical Society of America.