Twin-beam interference objective comprizes light path-dividing prism and reference mirror in first path and adjusted by tilter to set width and direction of interference bands.

摘要

A reference mirror (13) arranged in the first light path divided by the prism (12) between the objective lens and a specimen is angled by a tilter (14) so as to set the width and direction of the interference bands produced by the reflected light off the mirror and that off the specimen in the second light path as divided. A width setter rotates the reference mirror centrally round an axis parallel to the objective optical axis, maintaining a roughly constant interval between mirror and optical. A direction setter rotates the mirror centrally round the first optical path axis arranged so that width and direction setters can be serviced independently. A receiver drum in the tilter is joined to the objective lens containing the optical path divider and a second drum joined to the first accommodates the reference mirror, width setter and direction setter turning the second drum specified.