Optical device.

摘要

An optical spectrum multiplexer enabling rapid continuous spectral monitoring in a multipoint manufacturing process, said multiplexer comprising a plurality of light inlet slits (20) and light outlet slits (22) angularly spaced around a circular path, a diffraction grating (12) at the centre of the path, and a drum (14) having windows (16, 18) concentrically disposed between the said circular path and the grating, said grating and drum in use being rotated so that at any given instant light incident on the grating through one inlet slit is reflected to only one outlet slit.