Continuation of the study of reflecting diffraction grating by the application of holographic techniques

For a given wavelength, the angle of incidence for the optimum relative efficiency was sensibly the same for the various gratings independently of the Nb grooves/mm. In spite of the fact that all these gratings were blazed at the same wavelength this was not obvious a priori as the blaze angle varied from 1.71 deg for 600 gr/mm to 14.41 deg for the 5,000 gr/mm grating.