In this paper, we experimentally investigate the response of CYTOP-based multimode fiber interferometer to variations of the laser’s wavelength. We analyze the interferometric signals of the polymer CYTOP fiber with core diameter of 50 μm for lengths of 1 to 20 meters, using a commercially available FBG interrogator operating for wavelengths from 1510-1590 nm. The analysis was implemented using the averaged characteristics approach. In addition, the results of this work were compared with those of obtained using a silica-based multimode fiber interferometer.
Three methods of multimode fiber interferometer signal averaging are investigated theoretically and experimentally: the ensemble averaging, the averaging over a long realization, and the averaging over transverse coordinates of an output speckle pattern. The analysis is performed for two wavelengths and two launch conditions of the graded-index multimode fiber: few mode and multimode. Applicability of methods for practical applications is discussed.