ABSTRACT
Chaotic optical communication is of great significance for secure data transmission. Despite rapid development over the decades, high-speed (>100 Gbps) and long-distance (>100â km) chaotic optical communication in a single fiber is still full of challenges. Here, we propose and experimentally demonstrate high-speed and long-distance chaos-based secure optical communications using mutual injection of semiconductor lasers and space-division multiplexing (SDM) techniques. The encrypted signals are transmitted through all seven core channels of the multi-core fiber (MCF), which effectively expands the aggregate transmission capacity of a single fiber. A pair of source and synchronization devices based on mutual injection of semiconductor lasers are employed to effectively encrypt and decrypt signals. Chaos-based secure optical communications with 70-Gbps on-off keying (OOK) and 140-Gbps quadrature phase-shift keying (QPSK) signals over a 130-km MCF are successfully demonstrated in the experiment with favorable performance. The demonstration may pave the way for future ultrahigh capacity and ultra-long distance chaotic optical communications by fully exploiting multi-dimensional resources of light waves, including the spatial dimension.
ABSTRACT
Weakly-coupled mode division multiplexing (MDM) techniques supporting intensity modulation and direct detection (IM/DD) transmission is a promising candidate to enhance the capacity of short-reach applications such as optical interconnections, in which low-modal-crosstalk mode multiplexers/demultiplexers (MMUX/MDEMUX) are highly desired. In this paper, we firstly propose an all-fiber low-modal-crosstalk orthogonal combine reception scheme for degenerate linearly-polarized (LP) modes, in which signals in both degenerate modes are firstly demultiplexed into the LP01 mode of single-mode fibers, and then are multiplexed into mutually orthogonal LP01 and LP11 modes of a two-mode fiber for simultaneous detection. Then a pair of 4-LP-mode MMUX/MDEMUX consisting of cascaded mode-selective couplers and orthogonal combiners are fabricated with side-polishing processing, which achieve low back-to-back modal crosstalk of lower than -18.51â dB and insertion loss of lower than 3.81â dB for all the 4 modes. Finally, a stable real-time 4 modes × 4λ × 10 Gb/s MDM-wavelength division multiplexing (WDM) transmission over 20-km few-mode fiber is experimentally demonstrated. The proposed scheme is scalable to support more modes and can pave the way to practical implementation of IM/DD MDM transmission applications.
ABSTRACT
We present a rapid and precise method to design the multiple step-index bridge fiber for ultra-low insertion loss few-mode multi-core fiber Fan-in/Fan-out device. The genetic algorithm is applied to optimize the structural parameters to support multi-mode operation. Based on the proposed intelligent iteration platform, core-based multiplex/demultiplex optimization can be achieved with less than 1.0 dB insertion loss for the first 6 LP modes in space division multiplexing system consisting of few-mode multi-core fibers. Besides, we have successfully drew the designed bridge fiber and fabricated the corresponding Fan-in/Fan-out device. When connecting it with the single-core 6-mode fiber and 7-core 6-mode fiber, the average insertion losses of mode LP01, LP11a, LP11b, LP21a, LP21b, and LP02 are 0.88â dB, 1.11â dB, 1.07â dB, 1.42â dB, 1.33â dB, and 1.04â dB, respectively.
ABSTRACT
The dried rhizome of Musa basjoo Sieb. et Zucc. is Rhizoma Musae. It has been used to treat diabetes in Miao medicine in China. Lupenone was isolated from Rhizoma Musae and has good anti-diabetic activity. Its mechanism of action is unclear. Diabetes is a chronic low-level systemic inflammatory disease, and lupenone has anti-inflammatory activity, but the underlying mechanism is not fully elucidated. In this study, we aimed to construct the drug-target biologic network and predict the anti-inflammatory mechanism of lupenone. The network-based pharmacologic analysis platform was used to identify the target proteins related to inflammation. Furthermore, the effects of lupenone on acute, subacute and diabetic pancreatic inflammation were evaluated. The "component-target-disease" network was constructed using Cytoscape. Lupenone could regulate transcription factor p65, NF-kappa-B inhibitor alpha, transcription factor AP-1, NF-kappa-B essential modulator, nuclear factor NF-kappa-B p105 subunit, epidermal growth factor receptor, hypoxia-inducible factor 1-alpha and other proteins related to the PI3K-Akt, Toll-like receptor and NF-kappa B signaling pathways. In addition, lupenone significantly decreased acute and subacute inflammation in mice as well as the IL-1ß and IFN-γ levels in the pancreas of diabetic rats. The above results provide strong support for studying the molecular mechanism of lupenone in the treatment of diabetes from the perspective of anti-inflammation.