Abstract: A monochromator comprises an optical ray input section which limits the width of optical rays input from a light source, a first concave mirror for converting the optical rays passing through the optical ray input section into parallel rays, a diffraction grating for separating the parallel rays by wavelength into diffracted rays, a second concave mirror for condensing the diffracted rays when the diffracted rays are input, an optical ray output section which limits a wavelength band width of the condensed rays, and a substrate to which the optical ray input section, the first concave mirror, the diffraction grating, the second concave mirror, and the optical ray output section are fixed. A coefficient of linear expansion of a focal length of the first concave mirror, a coefficient of linear expansion of a focal length of the second concave mirror, and a coefficient of linear expansion of a material forming the substrate in the monochromator are approximately the same.

Abstract: The optical fiber positioning device (21) of the present invention is provided with: an optical connector main body (10) for supporting an optical fiber (3) which passes therethrough; a ferrule (2), which is provided coaxially with the optical fiber at the lead end side of the optical connector main body and through which the optical fiber passes; and a nut (9) which is disposed outside this ferrule.