High resolution spectrometer with grid defect correction has at least one of optical mirror with variable surface so that grid defects causing curvature of wavefront are compensated

摘要

The high resolution spectrometer (10) has an Echelle grid (12) and optical mirrors (18,20) at which the radiation passing via the grid is reflected. The surface of at least one of the optical mirrors is variable so that grid defects causing curvature of the wavefront (40) are compensated. The optical mirror is a plane mirror. A selected wavelength incident on the grid is dispersed to the mirror, reflected back and dispersed again. An independent claim is also included for the following: (a) a mirror arrangement for an inventive spectrometer.