Patent ID: 8902430
Filing Date: 2014-12-02
Classification: G01B

Abstract:
1. An apparatus comprising: a system configured to split a light emitted from a light source into reference light and subject light, cause the subject light to enter into an object, and combine the subject light reflected by the object with the reference light; a detection unit configured to detect coherent light between the combined subject and reference lights; an element, provided within a light path of the reference light or the subject light, configured to change a path length difference between the reference light and the subject light and a relative position between the reference light and the subject light in a light receiving surface of the detection unit; and a position-variable mechanism configured to cause a position of the element to be changeable; wherein, by changing the position of the element using the position-variable mechanism, the path length difference and the relative position are independently adjusted, wherein the element is movable in a first direction and a second direction vertical to the first direction, and wherein, the relative position changes according to a change of the position of the element in the first direction and the optical path length difference changes according to the change of the position of the element in the second direction.