Laser microinterferometry utilizing a multimode waveguide

Experiments were carried out to demonstrate the possibility of using a multimode waveguide in a fiber-optical hydrophone based on a Mach–Zehnder interferometer. It was found that multimode waveguides did not distort significantly the shape of the recorded signal and a change in the optical length of the waveguides under pressure was of the same order of magnitude as in the case of single-mode waveguides.