2-WAVELENGTH CONTOURING WITH A PULSED RUBY-LASER BY EMPLOYING TV-HOLOGRAPHY

A two-wavelength surface contouring system based on electronic speckle pattern interferometry (ESPI) with a pulsed ruby laser is reported. T wo states of the test object were recorded at different wavelengths of the laser. The wavelength change was controlled by altering the tempe rature of the output etalon. The phase information of the surface cont our can be obtained by using either the sinusoid fitting method or the Fourier transform method. Contour intervals of about 14 mm and 7 mm a re available.