| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wavelength shift measuring apparatus capable of measuring fluctuation of an optical source wavelength with accuracy and resolution of not greater than pm by being equipped with a construction in which an optical path difference of two light beams stably becomes constant. <P>SOLUTION: A wavelength shift measuring apparatus is a wavelength shift detector WLCD1 which measures a shift of a wavelength of a light beam emitted from a light source, and includes a beam splitter BS2 splitting the light beam emitted from the light source into a plurality of light beams and to synthesize two light beams among the plurality of light beams to generate an interference light, a spacer member SP provided so that an optical path length difference of the two light beams split by the beam splitter PBS2 is constant, and a plurality of photoelectric sensors PDA+, PDB+ detecting the interference light generated by the beam splitter BS2. The plurality of photoelectric sensors PDA+, PDB+ output a plurality of interference signals having phases shifted from one another based on the interference light to measure a wavelength shift using the plurality of interference signals. <P>COPYRIGHT: (C)2010,JPO&INPIT |
