Monochromator

Abstract

A monochromatorincludes: a diffraction gratingplaced within a housingso as to receive light from an entranceand disperse the light into a spectrum from which a component of light having a set wavelength is to be extracted through an exit; an optical filterto be removably inserted between the grating and the exit to remove light within a specific wavelength band which is out of the set wavelength; a rotary drivefor rotating the grating using a stepping motor; a wavelength-movement information setterwhich sets wavelength-movement information to be used for rotating the grating from an original position to a rotational position corresponding to the set wavelength; and a wavelength-movement controllerwhich controls the rotary drive to initially rotate the grating to the original position and subsequently rotate it to the aforementioned rotational position based on the wavelength-movement information.