Spatiotemporal phase unwrapping and its application in fringe projection fiber optic phase-shifting profilometry

A spatiotemporal phase unwrapping method is proposed that combines the dynamic optic fiber interferometric fringe projection method and the phase-shifting technique. A fringe projection fiber optic phase- shifting interferometer was set up, in which the fringe spacing and rotation can be easily adjusted. In the first step of the spatiotemporal phase unwrapping method, a large effective wavelength can be chosen so that the phase jump at the discontinuous profile is less than ?, then the spatial phase unwrapping method can be applied. Several intermediate phase maps can be obtained by changing fringe pitch and fringe orientation, reducing the effective wavelength step by step, and unwrapping each pixel along the time axis. In the final step, a high precision result can be obtained. A minimum number of steps can be chosen to obtain the required accuracy according to the conclusion presented. An experimental result is presented for the measurement of a discontinuous object and shows the validity of the proposed method.

[1]  D. J. Brangaccio,et al.  Digital wavefront measuring interferometer for testing optical surfaces and lenses. , 1974, Applied optics.

[2]  R E Brooks,et al.  Moiré gauging using optical interference patterns. , 1969, Applied optics.

[3]  G. Häusler,et al.  Three-dimensional sensing of rough surfaces by coherence radar. , 1992, Applied optics.

[4]  Y Surrel,et al.  Design of phase-detection algorithms insensitive to bias modulation. , 1997, Applied optics.

[5]  M. Lalor,et al.  Robust, accurate seven-sample phase-shifting algorithm insensitive to nonlinear phase-shift error and second-harmonic distortion: a comparative study , 1999 .

[6]  Kieran G. Larkin,et al.  Design and assessment of symmetrical phase-shifting algorithms , 1992 .

[7]  E. Mathieu,et al.  Characterization and control of threedimensional objects using fringe projection techniques , 1975 .

[8]  J. M. Huntley,et al.  Temporal phase-unwrapping algorithm for automated interferogram analysis. , 1993, Applied optics.

[9]  Hsin-Chu Liu,et al.  Optical three-dimensional sensing by phase measuring profilometry , 1989 .

[10]  M. Takeda,et al.  Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry , 1982 .

[11]  Chris L. Koliopoulos,et al.  Fourier description of digital phase-measuring interferometry , 1990 .

[12]  H. Lèfevre,et al.  Single-mode fibre fractional wave devices and polarisation controllers , 1980 .

[13]  T. Eiju,et al.  Digital phase-shifting interferometry: a simple error-compensating phase calculation algorithm. , 1987, Applied optics.

[14]  Jonathan M. Huntley,et al.  Shape measurement by temporal phase unwrapping: comparison of unwrapping algorithms , 1997 .

[15]  D J Bone,et al.  Fourier fringe analysis: the two-dimensional phase unwrapping problem. , 1991, Applied optics.

[16]  J. D. R. Valera,et al.  Phase stepping in projected-fringe fibre-based moire interferometry , 1993 .

[17]  D R Burton,et al.  Multichannel Fourier fringe analysis as an aid to automatic phase unwrapping. , 1994, Applied optics.

[18]  Yushan Tan,et al.  Automated three-dimensional surface profilometry using dual-frequency optic fiber phase-shifting method , 1997 .

[19]  X. Su,et al.  Phase-stepping grating profilometry: utilization of intensity modulation analysis in complex objects evaluation , 1993 .

[20]  K. Hibino,et al.  Phase shifting for nonsinusoidal waveforms with phase-shift errors , 1995 .

[21]  David R. Burton,et al.  The use of carrier frequency shifting for the elimination of phase discontinuities in Fourier transform profilometry , 1995 .

[22]  V. Srinivasan,et al.  Automated phase-measuring profilometry of 3-D diffuse objects. , 1984, Applied optics.

[23]  Hong-Jun Su,et al.  Phase algorithm without the influence of carrier frequency , 1997 .

[24]  H Zhao,et al.  Phase-unwrapping algorithm for the measurement of three-dimensional object shapes. , 1994, Applied optics.

[25]  Mitsuo Takeda,et al.  Phase unwrapping by a maximum cross‐amplitude spanning tree algorithm: a comparative study , 1996 .

[26]  J M Huntley,et al.  Temporal phase unwrapping: application to surface profiling of discontinuous objects. , 1997, Applied optics.