Lulu Wang

Secure communications of CAP-4 and OOK signals over MMF based on electro-optic chaos

Chaos-based secure communication can provide a high level of privacy in data transmission. Here, we experimentally demonstrate secure signal transmission over two kinds of multimode fiber (MMF) based on electro-optic intensity chaos. High-quality synchronization is achieved in an electro-optic feedback configuration. Both 5u2009u2009Gbit/s carrier-less amplitude/phase (CAP-4) modulation and 10u2009u2009Gbit/s on-off key (OOK) signals are recovered efficiently in electro-optic chaos-based communication systems. Degradations of chaos synchronization and communication system due to mismatch of various hardware keys are also discussed.

MDM transmission of CAP-16 signals over 1.1- km anti-bending trench-assisted elliptical-core few-mode fiber in passive optical networks

Mode-division multiplexing passive optical network (MDM-PON) is a promising scheme for next-generation access networks to further increase the transmission capacity and number of end-customers. In this paper, we propose and experimentally demonstrate the implementation of MDM-PON architecture with the carrier-less amplitude/phase (CAP) modulation signals and two effectively separated spatial modes multiplexing transmission in an elliptical-core few-mode fiber (EC-FMF). The trench-assisted EC-FMF features favorable anti-bending performance with negligible power variations and stable mode intensity profiles under extreme bending conditions. Two spatial modes carrying CAP-16 signals for four users with net data rate of 5 Gb/s per user in the downstream transmission over 1.1-km EC-FMF is demonstrated. The measured mode crosstalk including mode (de)multiplexing and 1.1-km EC-FMF transmission is less than -18 dB and multiple input multiple output (MIMO) technique is not used in the experiment for simplicity. The measured optical signal-to-noise ratio (OSNR) penalties for the downstream transmission without or with crosstalk at a bit-error rate (BER) of 3.8x10-3 (7% forward error correction (FEC) threshold) are less than 1.8 dB and 3.1 dB, respectively. Larger transmission capacity and more users are expected when further employing higher dimension CAP signals and EC-FMF supporting more separable spatial modes.

Effect of Two Phase Mixtures on the Selection of the Discharge Path

This paper investigates the development, the breakdown process, and the discharge path selection of the lightning discharges while there exist two phase mixtures. 13 kinds of solid-gas mixtures and 3 kinds of liquid-gas mixtures are employed to study effect of two-phase mixtures (TPM) on the selection of the discharge path under lightning impulses. Grain size effects are shown upon these experimental results. When the diameter of solid or liquid grain is less than about 10 mum, the discharge path selects not TPM but air. And the discharge path selects TPM when the diameter is greater than about 100 mum. And the diameter is between about 10 mum and 100 mum, the discharge path selects TPM under negative lightning impulses, but it has a greater selection of air than TPM under positive lightning impulses. Volume fraction and permittivity of solid/liquid can also influence the selection of the discharge path.

Influence of Controller Parameters on Time Delay in Triggered Vacuum Switch

Three types of pulse transformers with different parameters were described for investigating the delay characteristics of the triggered vacuum switch (TVS). A design circuit for controlling the TVS is proposed herein. The experimental data show that the pulse transformer with low leakage inductance is of good performance in triggering the TVS. By means of changing the charge voltage and the capacitance of the controller, the delay and jitter times decrease with increasing the charge voltage and capacitance in a normal range. An optimal parameter was selected so that the delay and jitter times decrease to 4.6 mus and 1.4 mus, respectively.

Experimental Study on DC Corona Discharge in Air-solid Two Phase Mixture

This article makes research on the DC corona discharge generating in point-plane gaps of solid and gas materials, mainly studies the impact on the corona shape, corona discharge voltammetry after the adding of organic particles and inorganic particles. The solid materials are polypropylene powder and perlite powder, the physical characteristics as Figure 3.1.