{
  "$type": "site.standard.document",
  "description": "The present invention provides a measurement apparatus including a phase detection unit configured to detect, from interfering light of light reflected by a reference surface and light reflected by a test surface, a phase corresponding to an optical path length between the reference surface and the…",
  "path": "/patents/984162",
  "publishedAt": "2013-09-04T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "G01B9/02003",
    "CANON KK [JP]"
  ],
  "textContent": "The present invention provides a measurement apparatus including a phase detection unit configured to detect, from interfering light of light reflected by a reference surface and light reflected by a test surface, a phase corresponding to an optical path length between the reference surface and the test surface, a refractive index detection unit configured to detect a refractive index of a space between the reference surface and the test surface, and a processing unit configured to obtain the distance from a first phase and a first refractive index detected when the wavelength of light from the light source is a first wavelength, a second phase and a second refractive index detected when the wavelength of light from the light source is a second wavelength, and a third phase at a synthetic wavelength of the first wavelength and the second wavelength.",
  "title": "Absolute distance measuring multiwavelength interferometer"
}