Hartmann wave-front measurement at 13.4 nm with lambdaEUV/120 accuracy.
We report, for the first time to our knowledge, experimental demonstration of wave-front analysis via the Hartmann technique in the extreme ultraviolet range. The reference wave front needed to calibrate the sensor was generated by spatially filtering a focused undulator beam with 1.7- and 0.6-microm-diameter pinholes. To fully characterize the sensor, accuracy and sensitivity measurements were performed. The incident beam's wavelength was varied from 7 to 25 nm. Measurements of accuracy better than lambdaEUV/120 (0.11 nm) were obtained at lambdaEUV = 13.4 nm. The aberrations introduced by an additional thin mirror, as well as wave front of the spatially unfiltered incident beam, were also measured.
Mercère
Pascal
P
Laboratoire d'Interaction du Rayonnement X avec la Matière, Bâtiment 350, Université Paris-Sud, 91405 Orsay, France. mercere@enstay.ensta.fr
Zeitoun
Philippe
P
Idir
Mourad
M
Le Pape
Sébastien
S
Douillet
Denis
D
Levecq
Xavier
X
Dovillaire
Guillaume
G
Bucourt
Samuel
S
Goldberg
Kenneth A
KA
Naulleau
Patrick P
PP
Rekawa
Senajith
S