F. Tong

A novel bidirectional wavelength division multiplexed passive optical network with 1:1 protection

We propose a novel network architecture for WDM-PON which offers 1:1 protection capability. In case of any fiber cut between remote node and ONUs, the affected ONU can re-route the wavelength channels via the adjacent ONU.

Demonstration of data remodulation for upstream traffic in WDM access networks using injection-locked FP laser as modulator

We propose and demonstrate an upstream-traffic remodulation scheme based on injection locking of a FP laser diode on the downstream wavelength. The original 10 Gbit/s downstream data are largely suppressed, allowing simultaneous direct modulation of 1-Gb/s upstream data with improved signal quality.

Fundamental limitation and optimization on optical code conversion for WDM packet switching networks

Fundamental performance limitation originated from multi-access interference on a generic code converter for WDM packet switching networks is derived and analyzed. A closed-form optimal threshold value that yields the lowest code conversion error is also given.

All-optical wavelength conversion using active semiconductor devices

We report some of our recent results on all-optical wavelength conversion including result on broadband orthogonal pumped four-wave-mixing in semiconductor optical amplifiers and dual-wavelength injection-locking of a Fabry- Perot laser diode. The high speed performance of wavelength conversion buy dual-wavelength injection locking of a Fabry- Perot laser was investigated experimentally and we present for the first time results on wavelength conversion at 10Gbit/s using dual wavelength injection-locking of a Fabry- Perot laser diode. The experimental results for all-optical wavelength conversion using broadband orthogonal pumping in a fiber ring containing a semiconductor optical amplifier is described. We also describe the latest result on a 40Gbit/s polarization independent all-optical wavelength converter based on polarization diversity and four-wave-mixing in a single semiconductor optical amplifier.

Demonstration of an ONU for WDM access network with downstream BPSK and upstream remodulated OOK data using injection-locked FP laser

We propose an ONU for a WDM access network with 2.5 Gb/s passband BPSK downstream data and 1.25 Gb/s OOK upstream data. The downstream wavelength is reused to injection-lock a Fabry-Perot (FP) laser diode at the ONU to provide remodulation for the upstream data.

An optical-path supervisory scheme for optical cross-connects using pilot-tones

All-optical WDMA transport networks depend critically on the functioning of the optical cross-connects (OXCs) that are responsible for routing wavelength channels to their respective destinations. Failure of the optical switches in OXCs will route the channels to the wrong destinations, degrading the network performance. Fault detection in channel add-drop and routing is thus of vital significance. We propose an optical-path supervisory scheme for OXCs by imposing pilot tones onto input wavelength channels as channel identifications (IDs).

Demonstration of an add-drop network node with time slot access for high-speed WDMA dual bus/ring packet networks

Summary form only given. High-speed wavelength division multi-access (WDMA) ring and bus networks are very promising architectures to support multi-access of high-capacity data. Most WDMA networks are configured with fixed transmitter and tunable receiver (FTTR) and employ decentralized light sources. However, they require complicated control signaling and suffer from a wavelength matching problem. In this paper, we propose and demonstrate a practical WDMA ring/bus packet network node using tunable transmitter and fixed receiver (TTFR) configuration. Centralized light sources are used and time slot access is controlled by our proposed signaling scheme.

Exact analysis of homodyne-cross-talk-induced penalty in optical networks

Homodyne crosstalk causes severe system performance degradation in optical networks by beating with the desire signal. While Gaussian approximation overestimates the performance degradation, for a single dominant crosstalk source, the exact noise probability distribution and closed- form error probability is derived in this paper.

A novel FFT-based EDFA supervisory scheme for WDM transmission systems

We have proposed and demonstrated a novel EDFA (erbium-doped fiber amplifier) supervisory scheme for WDM transmission systems. The working status of multiple optical amplifiers can be monitored by analyzing the RF spectra of the common supervisory wavelength at the receiver end using a fast Fourier transform (FFT).

Polarization insensitive waveform restoration and channel crosstalk reduction in semiconductor optical amplifier gates using polarimetric filtering

We present a polarization-insensitive approach for waveform restoration in semiconductor-optical-amplifier (SOA) based optical gates using nonlinear polarization rotation in SOA and polarimetric filtering. The scheme is capable of suppressing the channel crosstalk owing to SOAs cross-gain-modulation for multiple input wavelengths.