WDM-PON has been considered a promising solution for future fronthaul links concerning new mobile networks applications. However, in order to avoid inventory problems and reduce operation costs, there is a need for colorless sources, where the same basic optical source can be used regardless of the desired wavelength. Also, the digital RoF scheme, which has been employed so far, might require a bandwidth that is prohibitive even for optical fiber links. In this paper, we propose and numerically investigate a bidirectional colorless WDM-PON fronthaul transporting analog RoF signals as an alternative to meet these demands. All simulations were performed using a framework calibrated with experimental data. For the downstream, we employ a double-cavity self-seeding technique, while the upstream is performed by a cascaded-RSOAs carrier-reuse approach. BER and EVM simulation analysis are presented for various data rates, modulations formats and RF bands ranging from 1 to 5 GHz, demonstrating the feasibility of our proposed topology as a novel fronthaul approach.

Wavelength‐division multiplexing passive optical network (WDM‐PON) is a promising solution to cope with the exponential data traffic growth, particularly regarding future mobile fronthaul. WDM‐PON schemes, based on self‐seeded wavelength agnostic transmitters using reflective semiconductor optical amplifiers (RSOAs), are seen as an option to provide an analog radio‐over‐fiber (A‐RoF) alternative to the current digital fronthaul. Although these A‐RoF have been already successfully demonstrated, it was observed that the arrayed waveguide grating (AWG)‐filtering characteristics affect both the optical seed generation and the radio signal integrity, requiring a design optimization. In order to do so, in this article, we optimize the A‐RoF transmission performance by comparing Bessel, Gaussian, and flat‐top AWG‐filter formats. The impact of seed linewidth and red‐shift on the signal error‐vector magnitude (EVM) and phase rotation is also investigated. We have found that EVM performance for BPSK and 16QAM transmission provided an improvement of 45% when compared to our previous results, with a phase offset of 0.8°, indicating little to no distortion, as a result of the selection of the optimal AWG filtering response.

No abstract

No abstract

Resumo A implementação de atividades práticas que envolvam cores constitui uma estratégia poderosa para estimular o interesse de crianças e adolescentes para a Ciência. Devido ao seu forte apelo visual e presença no cotidiano, as cores despertam a curiosidade dos estudantes e propiciam o aprendizado de conceitos fundamentais no campo da óptica, tais como reflexão, transmissão e refração. Nesse trabalho, descrevemos um programa de atividades desenvolvido para ensinar conceitos de óptica presentes na formação de cores a partir de materiais simples, baratos e acessíveis. Através de demonstrações abertas e discussões autônomas por parte dos estudantes, elucidamos o processo de formação de cores por reflexão e transmissão, bem como a razão pela qual se pode visualizar objetos incolores. As atividades aqui descritas foram apresentadas num evento de divulgação científica direcionado a crianças e adolescentes com idade entre 8 e 17 anos.