| 摘要 |
PURPOSE:To obtain a simple structure having few requirements for structural accuracy, by forming an interference image by luminous flux whose spectrum is to be measure, and performing the Fourier transformation of the output of the image pickup element which is arranged in an image plane of said interference image and has resolution in one dimension. CONSTITUTION:In an embodiment wherein a Fabry-Pe rot interferometer is used, a light source 1, a collimator lens 2, and an etalon 8, wherein two glass plates face to each other with a minute angle theta being formed, are provided. Therefore, when the image pickup device in one dimension is placed behind the etalon 8, a pattern which is determined by the spectrum of incident light is formed on the light receiving plane of the device 4. In the case the incident light is the light having a single wavelength, this pattern is a fringe pattern with a constant pitch. Since said pitch is proportional to the wavelength of light, the spectrum of the incident light is obtained by performing Fourier transformation of the image signal, which is obtained from the image pickup device when the incident light has an arbitrary spectrum, by a Fourier transformation element 7. |
