Wavelength scanning profilometry suitable for real-time surface shape measurement is proposed. A phase slope of the interference signal generated by a wavelength scan is measured at an individual image pixel on-line. The parallel outputs of these on-line measurements show a map of surface height in real time. Experiments where a tunable dye laser was used were conducted to simulate the real-time measurements of step objects with specular and diffuse surfaces. The results have shown that a height map is available at any moment during the wavelength scan, and the measurement accuracy of height increases as the scanning proceeds. For a scanning width of 25 nm, the accuracy was as high as 1 mum. Analyses of the measurement accuracy are given.

The accuracy and the measurement range of surface profilometry by wavelength scanning interferometry applied to diffusely reflecting surfaces are investigated. The influences of surface roughness and the imaging system in the interferometer are theoretically analyzed by derivation of the autocorrelation function of interferograms arising from wavelength scanning. By using a dye laser with a tuning range of 4.2 nm to a yield resolution of 39.1 mum, we have observed interferograms and their Fourier transforms and autocorrelations to study effects of defocusing and the size ratio of speckle to the CCD pixel for a plane diffuse object positioned normal to the incident beam.

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An algorithm for stellar object reconstruction without a reference star is described. The algorithm is based on parallel application of the iterative blind deconvolution method to several speckle frames, and it permits reconstruction of an object that satisfies the convolution relation in all the frames used. Computer simulations with noisy speckle images are carried out to demonstrate performances of the algorithm. The algorithm is applied to observational data of binary stars, and high-resolution images are clearly reconstructed. Binary parameters extracted from the images show good consistency with those obtained both with the power spectrum analysis and with the shift-and-add method.