Optical arrangement for use as e.g. moisture sensor, for sampling incident ray of automobile headlight, has optical grating diffracting incident ray into non-diffractive transmitted beam and transmitted diffraction beams

摘要

The arrangement has an optical grating (3) i.e. phase grating, arranged at a surface (2) of a transparent plate (1) in an incident region of an incident ray (4). The optical grating diffracts the incident ray into a non-diffractive transmitted beam (5) of in an order of zero and transmitted diffraction beams (6, 7) of first order. A detector acquires the diffraction beams exiting from the transparent plate. The transparent plate is formed over a cover plate of a headlight. The optical grating is formed at a sub-surface of an inner side of the cover plate.