Coherence functions on infinitesimal intervals are measured sequentially by detecting intensities after interfering with neighboring wave fields. They are combined arithmetically so that the coherence function over any desired interval is obtained. This method has special features: (i) the effect of turbulence in front of the detector can be eliminated; and, (ii) the coherence function over any distance can be obtained without physically expanding the span of the arm of the interferometer. The principal algorithm of coherence function derivation, discussions about the effectiveness and limitation of the method, and an application of the method are described.
© 1980 Optical Society of AmericaPDF Article