Optical arrangement, method of use, and method for determining a diffraction grating

An optical arrangement includes a light source which emits coherent light of a wavelength lambda, and a diffraction grating which has a multiplicity of diffraction structures which follow one another periodically at the spacing of a grating period d and are arranged along a base surface, the individual diffraction structures respectively having a blaze flank and an antiblaze flank, the blaze flanks being arranged at an angle beta and the antiblaze flanks being arranged at an angle alpha to the base surface, and respectively neighbouring blaze and antiblaze flanks enclosing an apex angle gamma, and an incident light beam being arranged at a Littrow angle thetaL relative to a grating normal of the diffraction grating. The angle beta of the blaze flanks to the base surface is selected as a function of the Littrow angle thetaL such that the diffraction efficiency is at least approximately maximal in one of the largest diffraction orders m, which still fulfils the condition (2((m+1)/m)-1)sin thetaL>=1, and for at least one polarization direction.