Patent ID: 6842252

Claim:
An interferometer wavelength meter for measurement of the unknown wavelength of an input beam with respect to the known wavelength of a reference beam comprising a flexural pivot defining a pivot axis, an oscillating bar pivotally mounted on said pivot and having a retroreflector thereon spaced from said pivot axis, means for effecting oscillatory reciprocal movement of said oscillating bar over an arc within the bending limit of said pivot, said arc defining the range of said movement, a fixed retroreflector having a reflecting surface spaced from said oscillating bar and parallel thereto when said oscillating bar is in a position intermediate to said arc, a fixed end mirror presenting a reflecting surface to the beam passing through the moving and fixed retroreflectors and defining an end of a folded optical path, means for defining a common path of propagation for said input and reference beams along a path containing said moving and fixed retroreflectors and turning upon reflection from said fixed end mirror, which path executes repeated changes in length as said oscillating bar executes said reciprocal oscillatory motion about said axis.