Abstract
Interferometry has traditionally been a highly useful tool for converting distance or phase information in a wave front to irradiance. With the coherence length of the source extending over many wavelengths, this mapping becomes strictly periodic resulting in an unambiguous range of only half of a wavelength. Using some version of phase shifting interferometry,1,2 this range can be extended to one wavelength. This ambiguity represents a serious limitation for such applications as profilometry, displacement measurement, and wave front sensing. These applications typically require processing of the resultant interferogram to obtain the desired range-sensitivity combination. This processing step is generally time-consuming precluding real-time measurements. We describe a new technique which allows real-time unambiguous measurement over a range of several wavelengths. The system combines polychromatic illumination with controlled phase shifting and employs very simple image processing steps.
© 1985 Optical Society of America
PDF ArticleMore Like This
Timothy C. Strand and Ernst Mueller
ThB3 Machine Vision (MV) 1985
Timothy C. Strand and Yigal Katzir
MW2 OSA Annual Meeting (FIO) 1986
Katherine Creath and James C. Wyant
THB4 OSA Annual Meeting (FIO) 1985