Even the best optics cannot deliver its promise if not perfectly aligned. With a very short wavelength, the alignment accuracy required increases dramatically as compared to visible light, imposing the use of at-wavelength wavefront sensors.
For more than a decade, Imagine Optic’s EUV and X-ray sensors have been demonstrated to be indispensable tools for tasks ranging from single optic alignment, such as an off-axis parabola and a toroidal mirror, to benders and active optics under grazing and normal incidences. Such a wavefront sensor facilitates the alignment of Kirkpatrick-Baez systems. Influence functions of the mirror to wavefront or phase profiles can be easily obtained in order to optimize a focal spot.
For in-line metrology, we provide HASO EUV and HASO HXR. Both wavefront sensors are based on our patented rotated square technology that ensures the highest possible wavefront spatial resolution and the highest possible spectral range.
An example of the improvement for 3 keV optics by wavefront metrology is shown in the figure above (Mercère et al, 2006). The wavefront is improved nearly 10 times after alignment, and the final spot size becomes symmetrical.
With a Hartmann wavefront sensor, it is possible to probe the X-ray beam quality instantaneously and in situ. Coupled to an active mirror, automatic adjustments can be performed to optimize the wavefront and the focal spot.