Diseño de filtro espectral SMS basado sobre el modo LP01 para la banda de 1.55 UM.

Abstract

This research stems from the desire to design an optical filter capable of effectively filtering at a wavelength of 1.55 μm using commonly used optical fibers, both single-mode and multimode. The goal is to achieve this without the need for additional components. To confirm the feasibility and performance of a seven-core spectral filter based on the fundamental propagation mode (〖LP〗_01) within the 1.55 μm wavelength range, a specialized fiber optic structure with a Singlemode-Multimode-Singlemode (SMS) core arrangement was developed using FimmWave software. The methodology employed combines both descriptive and applied approaches. Theoretical knowledge from the FimmWave software manual about circular waveguides was applied, encompassing considerations such as creating sections with specific lengths, coating width, individual core widths, refractive indices, couplings, and separation between cores. Experimental tests were conducted at a 3dB filtering bandwidth with normalized power levels, resulting in effective filtering at 1.55 μm. Graphs illustrating the behavior of different propagation modes highlighted the filter's operation primarily in the fundamental propagation mode (〖LP〗_01), exhibiting higher power. However, co-channel interference at a wavelength of 1.45 μm, attributed to mode 2, was observed, with other modes proving to be inconsequential. In conclusion, multiplexing has emerged as a viable solution for filter design, offering significant advantages such as increased transmission capacity, reduced costs, and improved optical system performance within the desired wavelength band. Moreover, it enables software users to streamline the design of circular guides with diverse fiber structures, thanks to the user manual developed for this purpose.