Interferometric applications of tunable lasers

摘要

Four different full-field interfeometric systems using variable laser wavelength are presented. The measurements of inplane displacements and strains on the surfaces of objects under load with the aid of the grating itnerfeometer and digital speckle pattern interferometer are described. Teh latter systel allows the determination of the amplitude and phase distributions of the modes of vibrating surfaces as well. The measurement of in-plane displacements of rough surfaces using scattered light beams and the determination of surface shape by heterodyne interferometry are presented. In the first three cases current modulated laser diodes currently modulated are exploited, in the last one - wavelength changes of laser radiation by acousto-optic modulators are introduced.