Km Of Conventional Fiber Research Articles

Dispersion compensation in a 24 × 20 Gbps DWDM system by cascaded chirped FBGs

A dispersion compensation scheme using the minimum number of cascaded fibre Bragg gratings (FBGs) is proposed for the transmission of 20 Gbps signal in 24 Wavelength Division Multiplexed (WDM) channels with a 0.4 nm channel spacing. The present work shows that four chirped FBGs (CFBGs) in cascade are sufficient to compensate the dispersion accumulated over 100 km of conventional fibre. The parameters of the CFBGs are optimized to obtain maximum quality factor for all the channels. The proposed setup is effective for simultaneous dispersion compensation in a WDM transmission system.

Highly dispersed pulses for 2 × 40 Gbit/stransmission over 800 km of conventional singlemode fibre

Two-channel 40 Gbit/s transmission over 800 km of conventional fibre is reported. Return-to-zero 2.5 ps pulses are used to minimise self-phase-modulation effects, enabling 80 km amplifier spacing, and allowing dispersion compensation to be carried out entirely at the receiver.

16-channel 50 GHz channel spacing long-haultransmitter for DWDM systems

A 16-wavelength transmitter with 50 GHz channel spacing was built by interleaving two externally modulated singlemode 8-channel waveguide-grating-router multifrequency lasers. A power penalty of < 0.4 dB was measured on all channels modulated at 2.5 Gbit/s after transmission through 627 km of conventional fibre (17 ps/km/nm).

Comparison of resistance to polarisation mode dispersionof NRZ and phase-shaped binary transmission formats at 10 Gbit/s

The purpose of the reported 10 Gbit/s experiments is to compare the resistance to severe polarisation mode dispersion (PMD) exhibited by a link of 63.4 km of conventional fibre, for two different modulation formats: non-return-to-zero (NRZ) and phase-shaped binary transmission (PSBT). It clearly appears that the PSBT format is far more resistant to PMD than the NRZ modulation format.

Phase-engineered III-V MQW Mach-Zehnder modulators

We have optimized the negative frequency chirp while maintaining a high extinction ratio in an InP-InGaAsP multiple-quantum-well (MQW) Mach-Zehnder modulator. Our procedure is to elongate one modulator arm such that a /spl pi/ phase shift is produced at zero bias relative to the opposing arm. The resulting de extinction ratio is improved to /spl ap/16 dB from 10 dB relative to a symmetric design. The frequency chirp of the modulator at the rising edge is about -3 GHz enabling excellent transmission performance over a 95 km of conventional fiber.

2.5 Gb/s transmission over 674 km at multiple wavelengths using a tunable DBR laser with an integrated electroabsorption modulator

We present a distributed Bragg reflector (DBR) laser/modulator photonic integrated circuit capable of transmission over 674 km of conventional fiber at 2.5 Gb/s. Transmission was performed at four wavelengths over a range of >4 nm. The bit error rate (BER) sensitivity achieved at each wavelength varied by less than 1.1 dB. These results produce a record bit rate-distance product at each wavelength of 1.7 Tb.km/s for monolithic transmitters through nondispersion shifted fiber. Such devices are ideal sources for multichannel wavelength-division-multiplexed (WDM) transmission systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Directly modulated DBR lasers for long-haul transmission at 1.7 Gbit/s

Abstract We demonstrate 1.7 Gbit/s transmission through 257 km of conventional fiber using directly modulated distributed-Bragg reflector (DBR) lasers and fiber amplifiers. This experiment resulted in a record bit rate distance product of 437 km Gb/s for direct modulation at rates between 1 and 3 Gbit/s. This paper has been accepted for presentation at OFC '92.

Dispersion penalty reduction using an optical modulator with adjustable chirp

Using a unique Ti:LiNbO/sub 3/ modulator, the value of the modulation chirp parameter that minimizes the transmission power penalty caused by fiber chromatic dispersion was experimentally identified. System experiments at 5 Gb/s using nonreturn-to-zero (NRZ) amplitude-shift-keyed (ASK) transmission with direct detection reception are discussed, and the optimum values of the modulation chirp parameter versus distance for transmission at 1.5 mu m wavelength over fibre having zero dispersion at 1.3 mu m are identified. 5 Gb/s NRZ transmission was achieved through distances of 128, 192, and 256 km of conventional fiber while incurring dispersion penalties of -0.5, 0.1, and 1.1 dB respectively, by operating at the quantum chirp value.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>