Abstract: The speckle shearing interferometry applied in optical nondestructive detection on compesite materials is accompanied with a significant wide range of loading that willl be of bene-fit to such whole-field observations that no defect could be avoided Intensity distribution of shearing interferometric frin ge(equistrain fringe)is presented in a more general way,which shows that its density increases more slowly than that of holographic interferometric fringe(equi-displacement fringe)as the loading increases.An adjustable sensitivity characterized by the shearing fringe itself will additionally broaden the loading range greatly.Experimental obserVations agree with the analyses.

Key words: holographic interferometry, nondestructive tests, shearing, laser interferometry