A grazing-incidence spectrometer-monochromator for diagnostics and application of the extreme-ultraviolet (EUV) and soft-x-ray high-order harmonics generated by the interaction between a few-optical-cycle laser pulse and a gas jet has been fabricated. We address the necessity of high-resolution spectral and spatial analyses of the high-order harmonics as well as their use as short EUV backlighters in pump-probe experiments. The spectrometer that we present uses a variable-line-spaced flat grating illuminated in the converging light coming from a toroidal mirror. The spectrum is stigmatic, and the focal surface is almost flat in a wide spectral region. The detector is a microchannel plate intensifier with a phosphor screen optically coupled to a CCD camera; it can be moved by means of a linear drive to acquire different portions of the spectrum in the 5–75-nm region. The resolution is almost limited by the pixel size of the detector. We apply the same optical scheme to achieve a constant-deviation-angle monochromator by substituting an exit slit for the detector block: The rotation of the grating gives the spectral scanning. A monochromator for the 5–50 nm spectral region is achieved.
© 2003 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(120.6200) Instrumentation, measurement, and metrology : Spectrometers and spectroscopic instrumentation
(190.7110) Nonlinear optics : Ultrafast nonlinear optics
(300.6540) Spectroscopy : Spectroscopy, ultraviolet
Luca Poletto, Giuseppe Tondello, and Paolo Villoresi, "Optical Design of a Spectrometer-Monochromator for the Extreme-Ultraviolet and Soft-X-Ray Emission of High-Order Harmonics," Appl. Opt. 42, 6367-6373 (2003)