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

摘要

An optical arrangement has a light source which emits coherent light of a specific wavelength. Further provided is an optical Littrow grating, arranged at a specific Littrow angle &thgr;_L. It has a multiplicity of parallel diffraction structures following one another periodically at an interval in each case of one specific grating period and arranged on a substrate predetermining a base area. The light wavelength, the grating period and the Littrow angle &thgr;_L are tuned to one another in such a way that the grating is used in one of the largest diffraction orders m for light reflected back at the Littrow angle &thgr;_L, which still fulfils the condition:; $PTEXTPDAT(2(/PDATHILITALICPDATm/PDAT/ITALIC/HILPDAT\+1)//PDATHILITALICPDATm/PDAT/ITALIC/HILPDAT\−1)\; sin\; (\&thgr;/PDATHILSBPDATL/PDAT/SB/HILPDAT)\≧1\; /PDAT/PTEXT$ ;An optical arrangement of this kind has an increased reflection efficiency.