In coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems, the high peak-average-power ratio (PAPR) is the major disadvantage that impacts the system performance, which is manifested in limiting the maximum power of lasers and exacerbating the fiber nonlinear effects. Therefore, a novel PAPR reduction scheme using improved selective mapping (ISLM) cascading neural network (NN)-based companding algorithm is proposed. Compared with the original OFDM and the single traditional scheme, the proposed scheme shows better PAPR reduction effect and bit error rate (BER) performance. Compared with the cascaded scheme, the proposed scheme has the similar effect but lower complexity.
The recently presented coherent point-to-multipoint transceivers (P2MP-TRXs), which are enabled by digital subcarrier modulation, have been viewed as a promising substitute for the point-to-point transceivers, especially for the network segments with hub-and-spoke traffic patterns. This paper studies the network planning of wavelength-switched optical networks with P2MP-TRXs, which includes correlated routing and spectrum assignment, placement of P2MP-TRXs in groups and corresponding subcarrier assignments. We design an efficient heuristic to find near-optimal solutions in polynomial time.
An all-optical plasmonic modulator working at visible wavelengths based on graphene/black phosphorus heterostructure is proposed. This modulator is capable of operating from $400 \mathrm{~nm}$ to $800 \mathrm{~nm}$ with large extinction ratio up to $55 \mathrm{~dB}$.
A bandwidth and wavelength tunable filter and its application in fiber lasers are demonstrated. The continuous wavelength-tunable and the start-up and extinction dynamics of pulse in the Mamyshev oscillator have been studied with the filter.
In this paper, we propose and experimentally demonstrate a refractive index (RI) sensing system using an extrinsic Fabry-Perot interferometer (EFPI) structure based microwave photonic filter (MPF). Two EFPI sensors with cavity lengths of $500 \mu \mathrm{m}$ and $960 \mu \mathrm{m}$ have been fabricated, and the sensitivities of 627.953 MHz/RIU and 1201.653 MHz/RIU have been achieved, respectively. The proposed sensing system has the advantages such as high sensitivity, good linearity, and enlarged measurement range.
