SPECTROMETER AND SPECTROMETRIC METHOD
The present invention provides a spectrometric method in which groups of light beams (also referred to as "object beams"), such as scattered light or fluorescent light which occurs radially in various directions from each bright spot in a region being measured (S1), are incident upon an objective lens (12) and turned into bundles of collimated beams to reach a phase shifter (14). Then, after having been each reflected on a reference mirror unit (15) and a tilted mirror unit (16) of the phase shifter (14), the beams form an interference figure through an image-forming lens (18) on a light-receiving surface (20a) of a detector unit (20). At this time, there exists a continuous optical path difference distribution between the group of light beams reflected on the reference mirror unit (15) and the group of light beams reflected on the tilted mirror unit (16), and therefore, when the optical intensity of the interference figure on the light-receiving surface (20a) is detected, an interferogram with the optical intensity continuously varied (the waveform of variations in image-forming intensity) is obtained. By a Fourier transform of this interferogram, it is possible to acquire spectral characteristics or a relative intensity of each wavelength of the light beams emitted from the bright spot of an object being measured (S).