DESIGN METHOD FOR SPECTROGRAPH AND SPECTROGRAPH

摘要

Disclosed are a design method for a spectrograph and a spectrograph. A concave grating (G), three incidence slits (A1, A2, A3) and three optical detectors (B11 B12, B21 B22, B31 B32) are used for setting up the spectrograph. The design method comprises the following steps: (1) determining an incidence angle of a second incidence slit and a grooved period of the concave grating; (2) estimating a blaze angle of the concave grating, and determining a surface material and a grooved structure of the concave grating; (3) acquiring a wavelength-diffraction efficiency curve of the concave grating under a plurality of angles when the incidence angle is θA2; (4) determining values of incidence angles θA1 and θA3 and values of wavelengths λ2 and λ3, and making λ4 equal to λ5; (5) obtaining recording structural parameters and application structural parameters; (6) determining manufacture parameters of the concave grating; and (7) determining positions of the three incidence slits and three optical detectors with respect to the concave grating, and setting up the spectrograph. The spectrograph obtained by means of the design method has relatively high diffraction efficiency in a majority of spectrum areas, thereby effectively solving the problem that the diffraction efficiency in a wide spectrum area is relatively low.