In this paper, a method is proposed, in which the optical path modulations in a fiber-linked telescope array can be generated by stretching fiber arms. The mechanism of this method and the problems introduced by stretching fibers, such as polarization effects,dispersion effects, are analysed. To demonstrate this method, an experimental setup is established in which the two arms of a Mach-Zehnder interferometer are replaced by two pieces of fibers. One iR glass fiber arm is wrapped onto a piezoelectric tube. Another silicon fiber arm is wrapped freely. Experiments have been done. Experimental results are briefly discussed.