Improvements in and relating to grating monochromators

摘要

1,129,685. Monochromators. SIR HOWARD GRUBB PARSONS & CO. Ltd. Oct. 6, 1966 [Oct. 22, 1965], No.44916/65. Heading G2J. A monochromator comprising two rotatable diffraction gratings G 1 , G 2 , an entrance slit S 1 , an exit slit S 2 , and collimating and condensing elements associated with each grating, is provided with beam switching means located permanently in the beam path for directing light from the entrance slit S 1 on to a selected one of the two gratings and subsequently towards the exit slit S 2 . In the arrangement of Fig. 1 two mirrors M 5 , M 6 are rotatably mounted adjacent the two slits S 1 , S 2 so as to direct light towards the slit S 2 , via a concave mirror M 1 , the grating G 1 , and a concave mirror M 3 or via a concave mirror M 2 , the grating G 2 and a concave mirror M 4 . In a second embodiment Fig.2 (not shown) the gratings are arranged side by side and two rotatable concave mirrors are arranged to cooperate with either of the gratings.