High-resolution - littrow spectrometers and methods for the quasi - simultaneous determination of a wavelength and a line profile

摘要

In the case of a spectrometer with a dispersive element, which can be moved between at least two positions and on which, in the first position which is simply a selected wavelength radiation dispersed directly in the incident beam path falls back, is obtained in the second position of the dispersed radiation of the selected wavelength to a reflecting element, which is arranged such that the radiation of at least a further time by means of the dispersing element and then into the incident beam path can be steered back. In this case, a means, for example, a mirror, a echelle - grid or a prism for deflecting the jet of the dispersion plane is provided in such a way that the easily dispersed beam runs in a plane other than the multiply dispersed beam. The mirror is tilted about an axis parallel to the dispersion plane and perpendicular to the incident beam passes. Such a spectrometer is suitable for the determination of the spectral properties of an excimer laser for the photolithography. In the case of a method for measuring the radiation from a spectral range with a different spectral resolution, and in the case of which the beam of an imaging optical system onto a dispersion element is guided and of the dispersive element again is passed back to the imaging optics, the beam is by means of a change in the position of the dispersive element to a reflecting element, by which it is again ..