Patent ID: 7342664
Filing Date: 2008-03-11
Classification: G01J

Abstract:
1. A scanning interferometer which comprises: (a) a beamsplitter; (b) a first reflector separated from the beamsplitter by a first optical path for passage of a first beam of electromagnetic radiation; (c) a second reflector separated from the beamsplitter by a second optical path for passage of a second beam of electromagnetic radiation wherein the position of the second reflector is selectively adjustable to selectively adjust the length of the second optical path and wherein the first and second optical paths intersect at the beamsplitter to allow recombination of the first and second beams of electromagnetic radiation; (d) an actuator which functions for selective adjustment of the length of the second optical path wherein the actuator converts rotational displacement of at least one rotatable element into linear displacement of the second reflector, the actuator comprising: (i) a first rotatable element that is rotatable around a first rotation axis; (ii) a second rotatable element that is rotatable around a second rotation axis; (iii) a linker element upon which the second reflector is mounted where the linker element is rotationally coupled between the first and second rotatable elements at coupling points on the first and second rotatable elements, respectively, which are each offset from the first and second rotation axes, respectively, by the same offset distance; and (iv) a driving mechanism for rotating the first rotatable element; and (e) an optical detector for determining the length of the second optical path; wherein rotation of the first rotatable element actuates synchronous rotation of the second rotatable element which in turn actuates linear displacement of the linker element and the second reflector mounted thereon, without rotating the linker element and the second reflector with respect to a line intersecting the first and second rotation axes of the first and second rotatable elements; wherein the first and second rotatable elements are first and second pairs of spaced-apart concentric rotatable elements, respectively; and wherein the linker is positioned between the spaced-apart concentric rotatable elements and is rotatably coupled to each member of both pairs of the spaced-apart concentric rotatable elements.