Optical arrangement, Littrow grating for use in an optical arrangement and use of a Littrow grating

摘要

An optical assembly includes a light source, the coherent light (4, 5) of a specific wavelength emitted. Further, an optical Littrow grating (1) is provided, which is arranged at a certain Littrow angle theta _L. This comprises a multiplicity of parallel, periodically at intervals each having a predetermined grating period (d) successive diffraction structures (2) which are arranged on a base surface a predetermining carrier. The light wavelength, the grating period (d) and the Littrow angle theta _L are coordinated so that the grid (1) in one of the largest diffraction orders m is reflected back in the Littrow angle theta _L light (4, 5) is used, the still satisfies the condition: (2 (m + 1) / m - 1) sin (theta L) ≥ 1; Such an optical arrangement has an increased reflection efficiency.