Interferometric system with reduced vibration sensitivity and related method

Abstract

A source module ( 12 ) generates mutually orthogonally polarized beams of light as emanating from two spatially separated point sources (Sv, Sw) for use in a phase shifting interferometer.

1 . (canceled) 
     
     
         2 . An interferometric system of  claim 35 , wherein said interferometric module is configured to define a substantially common path for said beams between said source module and a reflective surface of said reference object. 
     
     
         3 . (canceled) 
     
     
         4 . An interferometric system of  claim 35 , wherein said reference beam emanated from one of said spatially separated sources and said test beam emanated from another of said spatially separated sources. 
     
     
         5 . An interferometric system of  claim 35 , wherein said reference and test beams received by said simultaneous phase shifting module substantially overlap each other. 
     
     
         6 . An interferometric system of  claim 35 , wherein the mutually orthogonally polarized beams are coherent. 
     
     
         7 . An interferometric system of  claim 35 , wherein there are two of said spatially separated sources. 
     
     
         8 . An interferometric system of  claim 35 , further 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . An interferometric system of  claim 35 , wherein said sources are virtual. 
     
     
         12 . An interferometric system of  claim 35 , wherein said sources are real. 
     
     
         13 . An interferometric system of  claim 35 , wherein the interferometry module further includes a nonpolarizing beamsplitter. 
     
     
         14 . An interferometric system of  claim 13 , wherein the nonpolarizing beamsplitter is positioned substantially between the source module and the reference object. 
     
     
         15 . An interferometric system of  claim 35 , wherein the interferometry module further includes a quarter waveplate positioned between the source module and the reference object. 
     
     
         16 . An interferometric system of  claim 15 , wherein the quarter waveplate is positioned substantially between the nonpolarizing beamsplitter and a collimator. 
     
     
         17 . An interferometric system of  claim 35 , wherein the interferometry module is of a Fizeau configuration. 
     
     
         18 . An interferometric system of  claim 8 , wherein the alignment module is positioned to intercept the beams between the interferometry module and the simultaneous phase-shifting module. 
     
     
         19 . An interferometric system of  claim 9 , wherein the imaging module is positioned to intercept the beams between the interferometry module and the simultaneous 
     
     
         20 . (canceled) 
     
     
         21 . An interferometric system of  claim 35 , wherein said polarization beamsplitter comprises a prism. 
     
     
         22 . An interferometric system of  claim 35 , wherein said polarization beamsplitter comprises a calcite beam displacer. 
     
     
         23 . An interferometric system of  claim 35 , wherein said polarization beamsplitter comprises two calcite beam displacers and a half waveplate. 
     
     
         24 . An interferometric system of  claim 35 , wherein the polarization beamsplitter comprises two fiber optics and cube polarizing beamsplitter. 
     
     
         25 . An interferometric system of  claim 35 , wherein the polarization beamsplitter comprises a polarizing lateral displacement beamsplitter. 
     
     
         26 . An interferometric system of  claim 35 , wherein the polarization beamsplitter comprises a cube polarizing beamsplitter and mirror. 
     
     
         27 . An interferometric system of  claim 35 , further comprising a filter to block said other portion of the beams from entering the simultaneous phase shifting module. 
     
     
         28 . An interferometric system of  claim 27 , wherein said filter is configured with an aperture to permit passage of said portion of the beams received by the simultaneous phase shifting module. 
     
     
         29 - 34 . (canceled) 
     
     
         35 . An interferometric system, comprising: a source module having a source of polarized light and a polarization beamsplitter configured to act on said polarized light to generate mutually orthogonally polarized beams of light; an interferometry module receiving said orthogonally polarized beams from said source, having optical elements, a reference object and a test object, said interferometry module further comprising a mechanism for manipulating a test beam and a reference beam into an overlapping position; a phase shifting module receiving a portion of said beams from said interferometry module to generate at least two phase-shifted interferograms substantially simultaneously from said test and reference beams, and an alignment camera which provides a view of relative positioning of the wavelengths and degree of overlap between them. 
     
     
         36 . An interferometric system of  claim 35 , wherein said polarized light from said source module is linearly polarized. 
     
     
         37 . An interferometric system of  claim 35 , wherein the mechanism for manipulating comprises a tip-tilt mechanism. 
     
     
         38 . An interferometric system, comprising: a source module having a source of linearly polarized light, and a polarization beamsplitter configured to generate mutually orthogonally polarized wavefronts as emanating from two spatially separated sources; an interferometry module receiving said orthogonally polarized wavefronts, said interferometry module having a test object and a reference, a beam splitter and a collimator, wherein orthogonally polarized reference wavefronts and orthogonally polarized test wavefronts exit the interferometry module; a tip-tilt mechanism for overlapping one of said orthogonally polarized reference wavefront with one of said orthogonally polarized test wavefronts; a simultaneous phase shifting module receiving said overlapping one reference wavefront and said one test wavefront from said interferometry module for generating at least two phase-shifted interferograms substantially simultaneously, wherein said wavefronts follow a substantially common path through said interferometric system. 
     
     
         39 . An interferometric system of  claim 38 , wherein said portion of said beams comprises mutually orthogonally polarized reference and test beams. 
     
     
         40 . An interferometric system of  claim 39 , wherein said reference beam emanated from one of said spatially separated sources and said test beam emanated from another of said spatially separated sources. 
     
     
         41 . An interferometric system of  claim 38 , wherein the mutually orthogonally polarized beams are coherent. 
     
     
         42 . An interferometric system of  claim 38 , wherein there are two of said spatially separated sources. 
     
     
         43 . An interferometric system of  claim 38 , further comprising an alignment module. 
     
     
         44 . An interferometric system of  claim 38 , further comprising an imaging module. 
     
     
         45 . An interferometric system of  claim 38 , wherein the source module includes a linearly polarized light source and a polarization beamsplitter configured to split linearly polarized light into said two mutually orthogonally polarized beams. 
     
     
         46 . An interferometric system of  claim 38 , wherein said sources are virtual. 
     
     
         47 . An interferometric system of  claim 38 , wherein said sources are real. 
     
     
         48 . An interferometric system of  claim 38 , wherein the interferometry module further includes a nonpolarizing beamsplitter. 
     
     
         49 . An interferometric system of  claim 48 , wherein the nonpolarizing beamsplitter is positioned substantially between the source module and the reference object. 
     
     
         50 . An interferometric system of  claim 38 , wherein the interferometry module further includes a quarter waveplate positioned between the source module and the reference object. 
     
     
         51 . An interferometric system of  claim 50 , wherein the quarter waveplate is positioned substantially between the nonpolarizing beamsplitter and a collimator. 
     
     
         52 . An interferometric system of  claim 38 , wherein the interferometry module is of a Fizeau configuration. 
     
     
         53 . An interferometric system of  claim 52 , wherein the alignment module is positioned to intercept the beams between the interferometry module and the simultaneous phase-shifting module. 
     
     
         54 . An interferometric system of  claim 44 , wherein the imaging module is positioned to intercept the beams between the interferometry module and the simultaneous phase shifting module. 
     
     
         55 . An interferometric system of  claim 38 , wherein the source module includes a polarization beamsplitter configured to interact with a beam from a source to provide said mutually orthogonally polarized beams. 
     
     
         56 . An interferometric system of  claim 55 , wherein said polarization beamsplitter comprises a prism. 
     
     
         57 . An interferometric system of  claim 55 , wherein said polarization beamsplitter comprises a calcite beam displacer. 
     
     
         58 . An interferometric system of  claim 55 , wherein said polarization beamsplitter comprises two calcite beam displacers and a half waveplate. 
     
     
         59 . An interferometric system of  claim 55 , wherein the polarization beamsplitter comprises two fiber optics and cube polarizing beamsplitter. 
     
     
         60 . An interferometric system of  claim 55 , wherein the polarization beamsplitter comprises a polarizing lateral displacement beamsplitter. 
     
     
         61 . An interferometric system of  claim 55 , wherein the polarization beamsplitter comprises a cube polarizing beamsplitter and mirror. 
     
     
         62 . An interferometric system of  claim 38 , further comprising a filter to block said other portion of the beams from entering the simultaneous phase shifting module. 
     
     
         63 . An interferometric system of  claim 62 , wherein said filter is configured with an aperture to permit passage of said portion of the beams received by the simultaneous phase shifting module.