The optical design of a high-throughput grazing-incidence flat-field spectrometer is presented. The spectral focal curve is almost a straight line because of the flat-field focusing properties of spherical variable-line-spaced gratings. The angular acceptance in the direction perpendicular to the plane of dispersion is maximized by means of a focusing spherical mirror mounted with its tangential plane coincident with the sagittal plane of the grating. Analytical calculations for the determination of the optimum mirror parameters are presented. A spectrometer for high-throughput experiments in the 800–60-eV region is designed with an extreme-ultraviolet-enhanced CCD detector: when the available flux is compared with that of a spectrometer with the same kinds of grating and detector but without a focusing mirror, the increase is as much as a factor 3.
© 2000 Optical Society of America
(050.1950) Diffraction and gratings : Diffraction gratings
(080.1010) Geometric optics : Aberrations (global)
(120.6200) Instrumentation, measurement, and metrology : Spectrometers and spectroscopic instrumentation
(220.1000) Optical design and fabrication : Aberration compensation
(260.7200) Physical optics : Ultraviolet, extreme
Luca Poletto and Giuseppe Tondello, "Design of a High-Throughput Grazing-Incidence Flat-Field Spectrometer," Appl. Opt. 39, 4000-4006 (2000)