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We experimentally investigate the impact of chromatic dispersion (CD), post-filtering effects (PFEs), and backreflection-induced penalties on intensityremodulation topologies based on self-seeded directly modulated reflective semiconductor optical amplifiers (RSOAs) acting as downstream carriers. Optical eye diagrams and power penalties as a function of link reach and reflection tolerances, as well as optical spectra and bit error rate (BER) performance up to 100 km, are measured and directly compared to a conventional prespectrum slicing light (PSSL) injection topology, in order to highlight the advantages and drawbacks of the self-seeding scheme. Downstream and bidirectional reaches up to 80 and 60 km, respectively, with a maximum 2 dB power penalty (for a BER of 10 −12 ) at 1.25 Gb/s operation are demonstrated in our self-seeding configuration, which enables enhanced resilience to CD and PFE effects while surpassing the conventional PSSL scheme in about 40 km.

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.

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In this paper, it is presented a comprehensive analysis of three optoelectronic oscillators circuits based on resonanttunneling diodes (RTD) for promising applications in terahertz frequency (THz) range. For all cases, it is investigated how each of these RTD devices performs under a wide range of the direct current (DC) voltages within the negative differential resistance region (NDR). The mathematical formalism developed here accounts for the effect of bias applied on the parameters of the reactive elements that composed the oscillators' small signal model. In this context, new expressions for evaluating the width of the depletion region of the devices are derived. Such mathematical formalism allows to make the performance analysis straightforward and show a close agreement to the device characterizations presented in the literature. Results pave the way for these RTD-based oscillators as potential candidates for Radio-over-Fiber (RoF) transmission, where higher operation frequencies will be major network requirements.