Nonlinearities in optical fibers deteriorate system performances and become a major performancelimiting issue. This article aims to investigate the compensation of nonlinear distortions in optical communication systems based on different wavelength propagations over few-mode fiber (FMF). The study adopted Space Division Multiplexing (SDM) based on decision feedback equalizer (DFE). Various transmission wavelength of the FMF system is applied to mitigate the attenuation effect on the system. In this paper, different wavelengths (780, 850 and 1550 nm) are used in SDM. Extensive simulation is performed to assess the attenuation and Bit Error Rate (BER) in each case. The results show that the wavelength of 1550 nm produces higher power and less attenuation in the transmission. Furthermore, this wavelength produces the best distance with less BER compared to 780 nm and 850 nm wavelengths. Moreover, the validations show improvement in BER and eye diagram.

Distributed Mode Loudspeakers (DMLs), as other electroacoustic transducers with electrodynamic excitation, are susceptible to the occurrence of nonlinear distortion. The literature on nonlinear distortion in DMLs is scarce. The vibrations of the DML panel are very small in amplitude, thus the coil excursion of the exciter is low, which is a favorable condition for low nonlinear distortion. The scope of this paper covers investigation of harmonic and intermodulation distortion, occurring in the DML. The harmonic distortion was examined with two methods and the intermodulation distortion – with three, including one author’s proposed method. The result indicate, that nonlinear distortion in DMLs may be a bigger problem than those in diaphragm loudspeakers.