| 摘要 |
PROBLEM TO BE SOLVED: To achieve an improvement in optical resolution and a reduction in a noise level in a spectroscopic sensor in which measurement target light is guided to a concave diffraction grating using an optical fiber, and the light subjected to wavelength dispersion is detected by a photodiode array to obtain information on a wavelength spectrum of the measurement target light.SOLUTION: In a spectroscopic sensor, a bundle fiber 4 is used as an optical fiber. A shape of an end face 4a of the bundle on an emission side is set as a rhombic shape that has one diagonal line thereof arranged along a direction in which grooves of a diffraction grating 2 are extended, and made function as a slit. Thereby, the optical fiber and the slit are substantially integrated with each other, which prevents a positional deviation from the slit caused by optical fiber eccentricity and also restricts measurement target light irradiation of a neighborhood of four corners having unsatisfactory accuracy of a shape of the diffraction grating 2. Consequently, an improvement in optical resolution and a reduction in noise level are attained. |
