To meet the ultra-bandwidth high-capacity communication, improve spectral efficiency and reduce the complexity of system structure, we have proposed the independent triple-sideband signal transmission system based on photonics-aided terahertz-wave (THz-wave). In this paper, we demonstrate up to 16-Gbaud independent triple-sideband 16-ary quadrature amplitude modulation (16QAM) signal transmission over 20 km standard single mode fiber (SSMF) at 0.3 THz. At the transmitter, independent triple-sideband 16QAM signals are modulated by an in-phase/quadrature (I/Q) modulator. Carrying independent triple-sideband signals optical carrier coupled with another laser to generate independent triple-sideband terahertz optical signals with a carrier frequency interval of 0.3THz. While at the receiver side, enabled by a photodetector (PD) conversion, we successfully obtain independent triple-sideband terahertz signals with a frequency of 0.3THz. Then we employ a local oscillator (LO) to drive mixer to generate intermediate frequency (IF) signal, and only one ADC is used to sample independent triple-sideband signals, digital signal processing (DSP) is finally performed to obtain independent triple-sideband signals. In this scheme, independent triple-sideband 16QAM signals is delivered over 20 km SSMF under the bit error ratio (BER) of 7% hard-decision forward-error-correction (HD-FEC) threshold of 3.8 × 10−3. Our simulation results show that the independent triple-sideband signal can further improve THz system transmission capacity and spectral efficiency. Our simplified independent triple-sideband THz system has a simple structure, high spectral efficiency, and reduced bandwidth requirements for DAC and ADC, which is a promising solution for future high-speed optical communications.
Achieving high−efficiency and stable hydrogen evolution from water splitting is a great challenge. Herein, a facilely prepared two−dimenssional self−supported catalytic electrode with excellent stability is constructed for large−scale hydrogen production from alkaline simulated seawater. The bifunctional catalytic electrode is prepared by a fast and mild one−step of sodium borohydride etching on a nickel foam (NF) substrate without adding other additives (NF@NiBx−3h). The overpotential of the hydrogen/oxygen evolution reaction (HER/OER) in alkaline−simulated seawater at 10 mA cm−2 is 96 mV and 261 mV. At 200 mA cm−2, the NF@NiBx−3h electrode shows good stability over 7 days throughout the water splitting process due to the corrosion resistance of the NF substrate, and strong adhesion between the Ni−B active material and the substrate. This work demonstrates a novel strategy for fabricating catalytic electrodes with high−performance, low cost and excellent stability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.