Xiangjun Xin

Fiber Dispersion Influence on Transmission of the Optical Millimeter-Waves Generated Using LN-MZM Intensity Modulation

We have theoretically investigated the transmission performance of the optical millimeter-waves (mm-waves) generated using intensity modulation via a Mach-Zehnder modulator, with the double and single sidebands (DSB and SSB) and optical carrier suppression (OCS) schemes. According to our theoretical analysis, fiber chromatic dispersion leads to fading effect and time shifting of the codes; therefore, signals are greatly degraded. Of all signals, DSB optical mm-wave suffers from both the fading effect and the time shifting of the codes. However, the optical mm-waves generated by SSB and OCS schemes are immune to the fading effect, while the time shifting of the codes limits their transmission distance. Experimental and simulation results confirm the theoretical analysis.

Optical millimeter wave generated by octupling the frequency of the local oscillator

What we believe to be a new scheme to generate an optical millimeter wave with octupling of the local oscillator via a nested LiNbO3 Mach-Zehnder modulator (MZM) is proposed and implemented by numerical simulation. Since the response frequency of the modulator and the local frequency are largely reduced, the bandwidth requirement of the transmitter to the optical and electrical components is reduced greatly. Then, the parameters of the nested modulator are analyzed theoretically, and we find that both the extinction ratio of the MZM and the phase imbalance between its two arms have influence on the performance of the generated optical millimeter wave.

A WDM-OFDM-PON architecture with centralized lightwave and PolSK-modulated multicast overlay

We propose and demonstrate a novel wavelength-division-multiplexing orthogonal-frequency-division-multiplexing passive-optical-network (WDM-OFDM-PON) architecture with centralized lightwave sources and polarization shift keying (PolSK) multicast overlay. The 10-Gb/s 16QAM-OFDM point to point (P2P) signal, 2.5-Gb/s multicast PolSK signal and 2.5-Gb/s on-off keying (OOK) upstream signal are experimentally demonstrated. After transmission over 25km standard single mode fiber (SMF), 1.5dB crosstalk between the downstream signals is eliminated by employing a low pass electrical filter at the PolSK receiver. The power penalty of the upstream OOK signal at BER of 10(-9) is less than 0.1dB.

A novel ECDM-OFDM-PON architecture for Next-Generation optical access network

This paper proposes a novel ECDM-OFDM-PON architecture for next-generation passive optical network. An error free bidirectional transmission of two PON channels has been successfully demonstrated in the experiment.

Physical-enhanced secure strategy in an OFDM-PON

We propose and experimentally demonstrate a physical layer enhanced OFDM access network based on chaos scrambling. An 8.89-Gb/s 64QAM-OFDM data with Logistic mapped chaos scrambling is transmitted over 25km successfully.

Dynamic λ-OFDMA with selective multicast overlaid

We experimentally demonstrate a dynamic ?-OFDMA with selective DPSK overlaid, and multicast control is realized through an alternative LO. The 10-Gb/s P2P signal, 2.5-Gb/s overlaid and 1.25-Gb/s upstream signal are transmitted 25km fiber successfully.

OFDM modulated WDM-ROF system based on PCF-Supercontinuum.

We have proposed a novel orthogonal frequency division multiplexing (OFDM) modulated WDM radio over fiber (ROF) system by employing a single photonic crystal fiber (PCF) supercontinuum (SC) multi-wavelength lightwave source. Both wired and wireless applications of ROF access are achieved. In our experiment, we pick out four 40-GHz ROF channels by properly designed fiber Bragg grating (FBG). The 1-Gb/s 16QAM-OFDM downstream signal is demonstrated for both wired and wireless applications over 20-km standard single mode fiber (SMF). A 1-Gb/s OOK upstream signal is also transmitted over 20-km SMF successfully with less than 0.4dB power penalty.

Physical secure enhancement in optical OFDMA-PON based on two-dimensional scrambling

This paper proposes a novel physical-enhanced chaotic secure strategy for optical OFDMA-PON based on two-dimentional scrambling. A 15.6-Gb/s encrypted 64QAM-OFDM data has been successfully demonstrated in the experiment.

A novel ECDM-OFDM-PON architecture for next-generation optical access network

This paper proposes a novel ECDM-OFDM-PON architecture for next-generation passive optical network. An error free bidirectional transmission of two PON channels has been successfully demonstrated in the experiment.

109.92-Gb/s WDM-OFDMA Uni-PON with Dynamic Resource Allocation and Variable Rate Access

This paper proposes a novel wavelength division multiplexing-orthogonal frequency multiple access (WDM-OFDMA) union passive optical network (uni-PON) architecture with dynamic resource allocation and variable rate access. It can offer an infrastructure with different access solutions. According to the quality of service (QoS) requirement of different services, the optical local terminal (OLT) can dynamically assign different resources as well as the access rates to different services. An experiment has been demonstrated with 4 wavelengths achieving combined signal at 109.92-Gb/s. A physical-layer adaptive algorithm is employed for the resource allocation and variable rate access. The different services with different resource allocations and variable access rates are also demonstrated in the experiment.