| 摘要 |
A Littrow grating (1) comprises a multiplicity of parallel diffraction structures (3) succeeding one another periodically. The latter are arranged on a support (2) defining a base area (4). A diffraction structure (3) comprises a blaze flank (5) inclined towards the base area (4) substantially at the Littrow angle (5). In addition the diffraction structure (3) comprises a counter-flank (6) which forms with the blaze flank (5) at the apex of a diffraction structure (3) an apex angle (alpha) which is less than 90°. The counter-flank (6) comprises at least two substantially plane area sections (7, 8). The latter extend, bordering one another and inclined relative to one another through an angle of inclination (beta), parallel with the extension direction of the diffraction structure (3). Due to the inclination of the at least two area sections (7, 8) relative to one another, the counter-flank (6) exhibits all in all a concave surface viewed from the light incidence side. A Littrow grating (1) of high reflectivity is obtained, which may be achieved with the removal of only a small amount of material at the manufacturing stage.
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