In recent years considerable attention has been devoted to the merging of radio frequency and optical fiber technologies aiming distribution millimeter-wave (mm-wave) signals. This effort given birth field Radio over Fiber (RoF) systems. sort systems have a great potential support secure, cost-effective, high-capacity vehicular/mobile/wireless access for future provisioning broadband, interactive, multimedia wireless services. this paper we present comprehensive review mm-wave RoF our...

We propose a novel low-complexity artificial neural network (ANN)-based nonlinear equalizer (NLE) for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) and compare it with the recent inverse Volterra-series transfer function (IVSTF)-based NLE over up to 1000 km of uncompensated links. Demonstration ANN-NLE at 80-Gb/s CO-OFDM using 16-quadrature amplitude modulation reveals Q -factor improvement after 1000-km transmission 3 1 dB respect linear equalization IVSTF-NLE, respectively.

We experimentally demonstrate ∼2 dB quality (Q)-factor enhancement in terms of fiber nonlinearity compensation 40 Gb/s 16 quadrature amplitude modulation coherent optical orthogonal frequency-division multiplexing at 2000 km, using a nonlinear equalizer (NLE) based on artificial neural networks (ANN). Nonlinearity alleviation depends escalation the ANN training overhead and signal bit rate, reporting ∼4 dBQ-factor 70 Gb/s, whereas reduction number neurons annihilates NLE performance. An...

Wireless communications with greater transmission capacities are possible in the millimeter wave (mmWave) region. However, to overcome significant propagation losses this frequency band, it is necessary employ more efficient and intelligent antennas based on MIMO beam-steering phased array technologies. This paper demonstrates fabrication of a beam steerable antenna using 4 × Butler matrix at 60 GHz employing metallic nanowire membrane (MnM) substrate. substrate has advantage interconnecting...

A reconfigurable nonlinear equalizer (RNLE) based on inverse Volterra series transfer function is proposed for dual-polarization (DP) and multiband coherent optical orthogonal frequency-division multiplexing (OFDM) signals. It shown that the RNLE outperforms by 2 dB linear equalization in a 260-Gb/s DP-OFDM system at 1500 km. The improves tolerance to inter/intraband nonlinearities, being independent polarization tributaries, modulation format, signal bit rate, subcarrier number, distance.

Coherent optical orthogonal frequency division multiplexing (CO-OFDM) has attracted a lot of interest in fiber communications due to its simplified digital signal processing (DSP) units, high spectral-efficiency, flexibility, and tolerance linear impairments. However, CO-OFDM’s peak-to-average power ratio imposes vulnerability fiber-induced non-linearities. DSP-based machine learning been considered as promising approach for non-linearity compensation without sacrificing computational...

A novel versatile digital signal processing (DSP)-based equalizer using support vector machine regression (SVR) is proposed for 16-quadrature amplitude modulated (16-QAM) coherent optical orthogonal frequency-division multiplexing (CO-OFDM) and experimentally compared to traditional DSP-based deterministic fiber-induced nonlinearity equalizers (NLEs), namely the full-field back-propagation (DBP) inverse Volterra series transfer function-based NLE (V-NLE). For a 40 Gb/s 16-QAM CO-OFDM at 2000...

The understanding of free-carrier dynamics in silicon photonic nano-waveguides and micro-cavities is fundamental to several nonlinear optical phenomena. Through time-resolved pump probe experiments, a complex carrier recombination revealed. Our results show that the lifetime varies as evolves, with faster decay rates at initial stages (with ∼800  ps) much slower lifetimes later (up ∼300  ns). large surface-to-volume ratio enables clear observation effect trapping, manifesting curve highly...

We propose a fast and non-destructive method to characterize the absolute diameter uniformity of micrometer-scale fiber tapers using pump probe forward Brillouin scattering setup. The fundamental torsional-radial acoustic mode supported by wire is excited pulsed laser oscillates at frequency that inversely proportional taper waist diameter. This standing time-varying wave induces polarization modulation on signal, whose spectrum structure reveals sample its non-uniformity. By comparing our...

This paper demonstrates a high-efficiency vertical grating coupler for the LP01x, LP11ax, and LP11bx modes of graded-index few-mode fiber. The is composed non-uniform straight bidirectional that was inverse-designed to address desired fiber modes, combined with two mode-selective directional couplers tapers. device fabricated by e-beam lithography minimum feature size 100 nm presented coupling efficiencies -3.0 dB, -3.6 -3.4 dB respectively. high efficiency proposed CMOS-compatible its...

Compact fiber-to-chip couplers play an important role in optical interconnections, especially data centers. However, the development of has been mostly limited to standard single mode fibers, with few devices compatible multicore and multimode fibers. Through use state-of-the-art optimization algorithms, we designed a compact dual-polarization coupler interface chips dense demonstrating, for first time, coupling both polarizations all cores, measured efficiency $-$4.3 dB 3 bandwidth 48 nm....

Phased arrays are expected to play a critical role in visible and infrared wireless systems. Their improved performance compared single element antennas finds uses communications, imaging, sensing. However, fabrication of photonic their feeding network require long separation, leading the appearance secondary radiation lobes and, consequently, crosstalk interference. In this work, we experimentally show that by arranging elements according Fermat's spiral, side lobe level (SLL) can be...

We report on time-resolved pump and probe characterization of linear nonlinear optical generation free carriers in a silicon strip nano-waveguide at the 1550 nm communication band. Analytical expressions were developed to extract carrier density averaged along waveguide length from measured free-carrier absorption for different input power levels. This allows us discriminate contributions two-photon (TPA) single-photon (SPA), obtaining TPA SPA coefficients (1.5 ± 0.1) cm/GW (1.9 m−1,...

Photonic antennas are critical in applications such as spectroscopy, photovoltaics, optical communications, holography, and sensors.In most of those applications, metallic have been employed due to their reduced sizes.Nevertheless, compact suffer from high dissipative loss, wavelength-dependent radiation pattern, they difficult integrate with CMOS technology.All-dielectric proposed overcome disadvantages because, contrast ones, CMOS-compatible, easier typical silicon waveguides, generally...

The effect of combined Lean Production (LP) and Cleaner (CP) on Environmental Operational Performance in emerging economies' industries has not yet been studied. To address this gap, work explores the LP CP practices performance. A sample 208 Brazilian organizations provided a set results to test four hypotheses: H1: are positively associated with industries; H2: performance is operational H3: environmental H4: industries. H1 was confirmed another three hypotheses were refuted, thus...

We demonstrate the insensitivity of envelope detection based mobile terminal to phase fluctuations RF signal. This property enables generation radio over fiber (RoF) signals heterodyning non-narrow linewidth laser and using direct modulation. report experimental up 2-Gb/s orthogonal frequency division multiplexing (OFDM) their transmission a 25-km long span modulation DFB lasers with combined 2.1 MHz resulting BER below 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

We experimentally demonstrate 7-dB reduction of nonlinearity penalty in 40-Gb/s CO-OFDM at 2000-km using support vector machine regression-based equalization. Simulation WDM-CO-OFDM shows up to 12-dB enhancement Q-factor compared linear

A novel artificial neural network (ANN)-based nonlinear equalizer (NLE) of low complexity is demonstrated for 40-Gb/s CO-OFDM at 2000 km, revealing ~1.5 dB enhancement in Q-factor compared to inverse Volterra-series transfer function based NLE.

A novel nonlinear equalizer based on a multiple-input multiple-output (MIMO) deep neural network (DNN) is proposed and experimentally demonstrated for compensation of inter-subcarrier nonlinearities in 40 Gb/s coherent optical orthogonal frequency division multiplexing system. Experimental results reveal that MIMO-DNN can extend the power margin by 4 dB at 2000 km standard single-mode fiber transmission when compared to linear or conventional single-input single-output DNN. It also found...